1) Itunes - sure there are plenty of great media players and what not for linux... but if you have an ios device whether its a new ipod, ipod touch, iphone, or ipad (and literally tens of millions of completely normal people do, they need itunes)."
Umm - my daughter uses I-Tunes on her Ubuntu machine. She's 17, and had no problem installing it and getting her ipod working.
2) TurboTax etc... yep its just one week a year. But millions of completely ordinary people do their taxes with this type of software.
LOL - been doing my Turbox Tax on the web under fedora and ubuntu for years. Cheaper than buying the CD's at the store. I have access to all of the forms and everything. Plus I dont have to waste space on my machine with software I only use once.
3) Miscellaneous Toys - from the child friendly Barbie photo manipulation software that came with the Barbie camera to setting up your new Logitech universal remote to an AppleTV to programming a Lego Mindstorms creation with LabView. This affects far more people than you might think.
Dont use any of those. Dont have any need, so I cant say if this is true or not.
4) Video games - Believe it or not, lots of perfectly normal people play everything from World of Warcraft,to Left4Dead, to the copy of Bejeweled or Riven they picked up at Walmart for $7 as an impulse buy.
I run 3d games all the time under Fedora. I used to use Ubuntu for games, but recently changed to gaming under Fedora. I run imprudence as well as others.
5) Peripherals - Printer fax scanner copier combination devices in particular still suck with linux. Getting printing going is usually relatively straightforward, but anything else is a complicated crapshoot.
I have an HP8180C. It prints, copies, scans. Never had any issue under Fedora or Ubuntu. I have a wireless Logitec mouse and keyboard connected to my Ubuntu machine. Never had any problem, Anything I connect to these machines works just fine. I also burn DVD movies under Ubuntu. Hook up my digital camcorder to my firewire port on my laptop running Ubuntu. Copy off all of my daughters high school events and burn them to cd's or DVD's for her and my wife.
I really wish people would stop with these old worn out generalizations. If you dont like Linux, fine dont use it. But please dont tell people that it wont work for anyone. It works fine for my family and many of my neighbours and friends.