To put it simply, the 360 is, well odd. The fact that it came out first among the three gaming companies (as compared to PS3 and Revolution), some people may be pulled into this, as noone really wants to wait..... You know, those "I'm gonna buy the first of the three systems that come out" people? Yeah. Those.
As for me, I feel that as the 360 came out first, it leaves less room for improvement. Sony and Nintendo are taking their time to making their systems better, while Microsoft just wants to ease their fans' anticipations earlier.
Of course, there are those people blinded to think that 360 is awesome, no matter what facts are thrown at them. For those, the 360 might be good, but for me, and hopefully other people, it didn't do as well as expected. I am sure at least a few people like anime games, which XBox almost rarely has. That, is where Microsoft fails. My feelings towards Microsoft entering the gaming industry will never change, until more anime games come out, but that's just my opinion.