SumthinRS, we did not said that live comment is the only way!
We pointed out that it takes talent (along with the most appropriate game) to make it enjoyable to watch if it is done live.
Off course if something is done well, it will be enjoyable to watch: I made the example of Minnesotaburns for somebody that does something different, even if it uses game footage for mere body, since his focus is on trolling.
What makes it hard, is that there are tons of channels out there with MW3 or other FPS, way too many, and almost nobody is doing something worth to be watched in my personal opinion.
If I have to watch somebody else play and talk over a game, it better be helpful because he explains things, amazing because I should say "I will never be that good", or funny because of the situation, glitch, trolling, etc.
Because to be honest, It is a videogame, and once it has been seen a few times, is gonna be the same thing over and over, expecially with the legion of kids that uploads videos of them shooting and play, thinking that putting music on them, and doing slo-mo, and video effects will make them do wonders.