Because like everyone else I do like a good bit of popcorn entertainment. I thought Avengers was a lot of fun. Upon examination, at least half of that script was total BS, but I don't always notice at first. Same with the trailer. I saw it, liked the fact it was moody, and was enthusiastic. Then some weeks passed, and I was talking to friends about it, and realized that Stark is a character that's already been played out. So has Bruce Wayne. And Peter Parker.. all those guys. Then I saw Cloud Atlas which has real ideas. I started writing, thinking, writing, and watching things again.
Then I realized that this new film is tripe, that it's cultural diarrhea, to borrow a phrase. I was pulled in like everyone else, there you have it.