But having to swap between either physical computers or dual-boot is just asking too much for me. I like my convenience. Having one OS that does whatever I want is good. Linux is getting closer with stuff like WINE, but I play too much obscure, old, heavily modded, or just games that have issues as it is - and don't want to add the OS into the mix. I like not having to worry about my OS being the problem. Just the other day I found out Old School Runescape's new launcher won't have Linux support, and I play that daily. :/
Some of the defaults in Windows suck, and I've had to disable some tracking and other crap I didn't like, but other than that it's been seamless for as long as I've had computers. That's good enough for me, even if it's a hodgepodge mess in terms of design.