You do realize that Iron Man defeats your whole argument right? They built good will through films that critics and GA agreed were good. IM2 was a problem, cleared up by the reception to the Avengers.
Batman Begins is actually another example that hurts your argument greatly, because it shows what bad films do to a good franchise. And what a great film like Batman Begins can do to bring it back to life. The multiplier and home media sales showed people were extremely happy with what they got. Then TDK happened.
IM3 was able to make as much money as a movie that: 1- Had a better critical reception; 2- Was the sequel of a movie with a better critical reception than The Avengers.
This pretty much proves that the quality of the movie itself is not as important as elements of mass appeal, like, for example, a family friendly tone, humour and a very charismatic lead. It's not that IM3 is a better movie than TDKR. It doesn't even need to be. That's the point. If you play-by-the-book you get a big pass. If you don't, different story.
Now, you bring Batman Begins into your argument for what? To help me prove my point that movies aren't soley judged by their quality? That factors other than people's opinions on the quality of the movie can help to make or break it? Well thank you.

) that the 2 most crazy fan bases are SW and Batman fans (Harry Potter 3rd are very far, but getting closer). You can talk trash about Batman or SW without a horde of fans going at your throat at a minute's notice. I was expecting the same kind of following and blind praise for BvS (It's actually comforting seeing that a bad movie didn't get a pass)