Well, it's simple. I don't want to get a super-powerful computer to play tf2. the Xbox 360 elite cost about $250 at Target, plus i got a free wireless controller. And, i can play tf2 with all my friends that have xbox live.
as for specifications:
Processor: IBM PowerPC 3 cores 3.2 GHz
RAM: 512 MB
hard disk drive: 120 Gb
Video Output: ATI Xbox 360 - 256-bit - 2D/3D graphics acceleration
Also, this is the wrong forums to be an asshole about people talking about video game systems. Go join SSLf if you want to do that.