It's all horses for courses.
I have 64-bit linux for my day to day use. It does everything I need to do and is pretty robust too. However, it doesn't do everything I want to do. Despite having nvidia's proprietary drivers, it's a crap gaming platform. Not because it isn't capable, but nobody really writes any decent games for it. And no, Doom3 and Quake4 don't really cut it. There's Wine, and related spin-offs, of course, but they don't really give bang up to date support.
No matter, people say. Get a console here. Never mind that the box I am running linux on has a quad core and what was a high end gfx card (now obsoleted by newer devices, but ho hum) and that I don't really want to fill my place with consoles.
So, I dual boot a 64-bit Windows. Vista, in fact (not purchased a copy of 7 yet). Does it give me any hassle? No. Does it play up to date games properly? Yes.
Considering that from a technical perspective, modern games are the most demanding desktop applications you are likely to run, stressing CPU, GPU and IO alike, it seems strange that an OS considered so darned awful would make such a good job of it, running titles for hours on end without any issues.