Yeah, the system that gave us even more of a glut than the feat system, where 90% of them were complete garbage and you die of boredom due to spamming them endlessly? And also, where they all felt magical and disconnected to the world you were in, because each one had implicit, uber-simplistic physics that the DM couldn't override or they were nerfing your toon?
The only thing the power system achieved for me in the end was a disdain for descriptions of the game world as "fluff". It made me feel bad about playing the game with real DMs. I wanted a videogame of those mechanics. When you get tired of the "fluff" of describing the action because they always "just work", why do you even need a DM? Write some code to do his job, and a random encounter generator and you can keep playing 4e till the end of time. DMs and even other PCs don't need to be humans, even, because computers can play the game just as well as people can (better, probably).
Ever hear of Deep Blue? Bet you any money a properly trained bot could p0wn a human in most encounters. But a team of PCs can almost always beat a DM in that system, they really don't stand a chance. That is the real reason why it failed. Players got bored of beating the DM all the time, and so did the DMs. It required tactics, not imagination. There's a difference. It took the literacy component out behind the shed and shot it.