If "workstation" is mentioned any time after about 1996 then more than one core/CPU is taken as a given.

but python is single threaded

Only if you use it that way.
Even a kids toy that came out years ago - the Nintendo DS - had multiple cores so if your code can benefit from being multithreaded but is not then you have some problems you should fix before pointing fingers at hardware.

Ever wondered why there is the phrase "stateful firewall"? It's as if that wasn't the only kind of firewall isn't it :)
The way you are using a list of allowed ports and hosts is a non-stateful firewall, just like very simple ipchains/iptables/ipfilter rules.

Escalate the situation up the tree until it reaches someone with a clue, or who can take advice from someone with a clue.
I had some phone system idiot that wanted to be able to telnet directly in without needing a password. The problem was almost self corrected forever when he took a open can of drink into the server room and put it down on a 5kW UPS. He muttered something about earth leakage circuit breakers upon being informed about how suicidal that was, totally unaware that 5kW of DC shorting directly through him would not have gone anywhere near such a thing.
Similarly the vendor mentioned here is expressing a view beyond their skill level.

I'm slightly surprised this is seen to be so universal

There used to be a big difference between the price of assembled computers and parts. Also computer assembly is now easier than putting together a flat pack coffee table.

but as an amateur, I'd end up with an amateurish job, and worry that I'd make some subtle error around cooling or power connections or whatever which would render the result unreliable or shorten its lifespan.

Maybe in 1995 but there are not many parts to put together now.

New cases are far better designed and do not demand the "blood sacrifice" that seemed to come with assembling a computer due to all of the sharp edges that used to be inside cases.

They still win on price per core all the way from the bottom (cheap 8 core) to the top end (a 64 core AMD system was around $10k while an 80 core Xeon was around $60k).

You can even do a quick dual screen workstation with just motherboard, memory, cpu, drives and case now plus SATA removes a lot of cabling hassle.
You only need dedicated video cards these days for recent 3D gaming, very high end CAD, or more than two displays. Even decoding compressed high quality video and pushing it out a HDMI connector something fairly standard motherboard graphics can do. Dedicated sound cards are something only musicians worry about now.

In my example above that should never have happened it was all perfectly legal but pissed off a shareholder of the "indie" record company and threatened their control of the market. In the current situation both ripping and downloading is opposed, once again not really on legal grounds but because it threatens control.
As written above "Ripping a CD for your own use is legal" - which is perfectly true in a lot of places, so there should be no legal grounds to oppose this music player in vehicles, it's effectively just the ripping bit of iTunes in a car. However it threatens control of a market so legal grounds are being searched for and it's seen as being a softer target than Apple.

We have a well-organized political-action group in this country, determined to destroy our Constitution and establish a one-party state

There has clearly been success in creating a one-party state. The party just happens to have two faces, but inside, there is no significant difference.

What's stupid is the author says "Technically, HTML5 isn’t a language". Um, yes it is. It is technically a Markup Language. That's kind've what the "ML" stands for.

He is conflating "programming language" with "language".

Comcast has two mantras. Increase sales and cut costs.

Comcast is cr*p at doing the latter. Why did it take a callout to my house in order to get my cablecard working? The online system and their attempt to authorize the cablecard when I called in both failed, but why? All that happened during the callout was that the technician called his buddy to send the signal to authorize the cablecard. Then he changed a few connectors in the wiring -- probably to justify the callout.

no, I could no longer justify the cost

That's the trick - convince salesfolk that there is no money in your pockets and you are dead to them. Sometimes it's worth them thinking you are an utter loser just so that they will leave you alone.
Asking telemarketers if there are any jobs available where they are used to be a good one - until those jobs moved offshore and now the trick no longer works.

I can't believe this idiocy is still going on

Imagine it's 1987. The local "indie" record company and the local record shops get together and roll out (incredibly expensive) CD burners that can burn discs of whatever the customers want from the catalogue of that "indie" record company for the price of a normal albumn. Launch day happened and suddenly everyone's knee deep in lawyers and the police are chasing customers out of the shop - the parent record company called the cops on their partly owned "indie" record company that turned out to not be as "indie" as everyone thought (especially after they owed a lot in legal costs).
There's been decades to stop the idiocy. People are ripping and downloading because of many missed opportunities, missed due to short term greed.

Yes there is that one and the French Mirage Jet way back, but that specific one I mentioned ruffled enough feathers to result in the US Senate spending a bit of time on it.

That time around 2000 with the tank targeting system was a true moment of black comedy when after that US technology was supplied from Israel to China it was mass produced and on-sold to Iran.
However blaming "Israel" for that one is like blaming the USA for Charles Manson - criminals exist and the thing was apparently stolen.