From "The Hacker Crackdown", Bruce Sterling, as linked above:

The day after the raid, Steve Jackson visited the local Secret Service headquarters with a lawyer in tow. There he confronted Tim Foley (still in Austin at that time) and demanded his book back. But there was trouble. GURPS Cyberpunk, alleged a Secret Service agent to astonished businessman Steve Jackson, was "a manual for computer crime."
"It's science fiction," Jackson said.
"No, this is real." This statement was repeated several times, by several agents. Jackson's ominously accurate game had passed from pure, obscure, smallscale fantasy into the impure, highly publicized, largescale fantasy of the Hacker Crackdown.

I'm not familiar with McAfee.
It is with F-Prot but I set it to run on Sunday nights, which may or may not be good practice. I really don't have enough MS Windows machines to be anything resembling a source of more than casual advice, most of the desktops and servers I work with are *nix boxes. I mostly use F-Prot because their linux version is good for scanning email for viruses and their MS Windows version doesn't seem to slow machines down unless you manually kick off a full scan. I don't know what their remote admin stuff is like because I'm never used it.

You're ridiculous. "Oh, I can just walk into a major bank

Only your stupid strawman is ridiculous, I'm suggesting that if you WORK at a major bank and you are responsible for their backups then part of that is being able to do bare metal recovery AND walk others through the process.
Yes, your strawman is stupid, but I didn't suggest anything remotely like your imaginary friend that you are shouting at and I have to admit that I think it's a very childish way to act.

While perhaps I should have been clearer and stated that with AMANDA you don't have to rely on dd and tar, the system is built in such a way that you can get by with as little as that if you have to in an emergency instead of installing and configuring that AMANDA software on a new machine first. While I wasn't clear enough I very much object to your over-reaction to that misunderstanding.

an artifact from my past whose knowledge and experiences are a subset of mine

With respect - professional engineer here, guy with a HR granted title of engineer there. You really should choose your insults a bit more carefully. I'm sure you have plenty of skills I do not have but to me IT in general is a subset of what I was doing last century, so you have only succeeded in making me laugh by puffing yourself up.

That's kind of my point.
Sometimes more important stuff has to be done before rendering something on the screen. Typically the thing that delays rendering (and everything else) is an IO task and often the user actually wants that to finish before they see anything. Sometimes it isn't related to what they want to see and that's where is gets annoying.
IMHO the idea of rendering before all else is why we get such braindead and counterproductive behaviour such as the control panel refreshing a few times before you can click on anything. It should have a high priority but it's not the only thing going on that the user wants to happen, otherwise you get insane race conditions like that control panel which a programmer from the 1960s could have pointed out as a bad idea.
I think it's better to wait and render once instead of rendering five or six times giving the user misleading information and slowing the whole thing down. We get fucked GUIs in 2015 purely due to poor programming practice led by poor assumptions since the hardware can deliver very fast rendering once we've decided what the user can see. It's not just MS Windows, it's really disappointing to compare an older gnome desktop on something like Centos5 to the current gnome - it goes from rock solid to the sort of thing that inspires complaints like yours about window drawing priority. Fluxbox or similar running applications not based on the new gtk+ on those same problematic machines go back to being rock solid.
So it doesn't seem to be X or the kernel, pushing things back on the application and library developers to get their shit together and give X something to render before the user gets pissed off with the wait.

That's really funny in a sad sort of way.
Not quite so slow as that (despite being called "slowaris") is the boot time for Sun servers that was made fun of in an inside joke on in the Stargate TV series. They have less than a minute to get the computer back online to get the gate open or they all die, then the scene changes to a screen showing the very start of a Sun sparc boot sequence - clearly they are utterly fucked at that point since it's going to be minutes of system checks before even the keyboard goes live.

Actually their multicore server CPUs are somewhat awesome and vastly cheaper than the Intel ones at this point, so mediocre doesn't fit.

Since AMD is a large company now that makes graphics hardware as well as CPUs I'd wager the graphics portion doesn't give a shit either way about "eating their own dog food", since it's not really theirs anyway.

F-prot, Avira and AVG don't seem to suffer from that.

acting somehow that 7 just came out last year and is all so new etc

It's only been three or so years that some major "workstation" software was ported to run on Win7/Vista/8 at all so some places only did migrate from XP in the last couple of years. Some people are still on XP in some workplaces. All it takes is a CD labelling program or similar bit of legacy software that won't work in win7 without some sort of virtual machine kludge (that users HATE since it breaks their desktop metaphor) and they stay stuck on XP. The new MS Office still works on XP so they have everything they need until they want stuff that needs a lot of memory, and some people are not hitting that barrier yet.

It is caused by poorly written programs that run as admin and write to the registry each time they run

Some people are still writing such shit TODAY.

He's looking for an excuse after the fact since the time expenditure would be less than he spent on the posts complaining about the time expenditure.

A bit less tinfoil, how about there being far less care taken with the old version than the new?
I'd add hardware requirements creep to that where the testers (don't laugh, I'm sure some testing is going on) have far more capable hardware than is typical for the install base. Not slow with an i7, SSD and 16GB or more of memory could be unacceptably slow on more typical Win7 hardware. Two cores and 2GB just don't seem to do it any more when it certainly used to for office tasks.

Does your other OS hold on to outdated versions of system files for compatibility reasons, like windows 7+ does?

Of course it does.
There's a thing called version numbers of libraries that predates MS but they didn't decide to go that way until relatively recently. It's a way of being able to retain old versions of system files for compatibility reasons without slowing down the system searching for stuff. That is why linux, solaris, oracle, mac, *bsd and everything else apart from MS can run old stuff without a great deal of mucking about.

New files get added during the day and old ones get modified so if you want to protect a malware-prone environment effectively there is going to be a lot of scanning activity during working hours.
An after hours scan reporting that a lot of stuff got trashed by cryptolocker at 10am is of very limited usefulness.

Or don't turn it off EVERY SINGLE FUCKING DAY, complain about it being slow to start, repeatedly, perhaps three times a week or more, but pointedly ignore advice not to turn it off EVERY SINGLE FUCKING DAY. I've got a few people who do that who don't have the patience of the above poster to have it turned on some time before they need to use it. Sometimes I think it's a work avoidance tactic to justify hanging around and chatting in the mornings.

Bucketloads of memory reduce the pain of running a malware-prone system since those on-access scans can be on a cached copy of the file instead of having to hit the actual disk twice.
Now we have desktop motherboards that can take 32GB of RAM relatively cheaply so what would have seemed excessive in the past is now a viable workaround.