I like to play games on my pc and reviews say you can't really play games well on a linux setup
That's what it basically comes down to.
Linux is great for servers, workstations and hobbyists. Windows is great for gaming. I am horribly generalizing there, but mainly how it applies to you.DirectX is very sophisticated and there's no competition to it on any other platform. You'll have to jump through hoops to get things working in Linux, and although it can be rewarding to get it working, it's just not practical.
I generally put Ubuntu on my older boxes as the main OS. I just like to tinker with it and try something different. There's not a lot of secrets/new windows maneuvers I don't know.
Not a big fan of partitioning hard drives to dual boot Windows/Linux, but I did that for a while.