Interesting take. I get what you are saying but I was into it, and loved the penultimate scene. The final scene, which detracted, should have been cut.

As often the case with science fiction I found the scientific errors distracting. Even if you were to blow something like that into fragments small enough that they all burned up in the atmosphere the result would be the same. Everybody would die. Unless they scattered them far enough so that almost all missed the earth, which would have been impossible by the time the second mission landed. I mean there's the earth looming in the background. The whole mess would have arrived minutes later. Oh well.

So even if they succeeded in breaking it up some time before it hit, nothing would be accomplished. The writers missed the moment. They could have had Jennier Lawrence and Leonardo Dicaprio running around trying to persuade people that even though the heroic capitalist nerd seems to have saved the day, everybody is still fucked. But then again everybody might as well die happy.