Incredi-Bulok and Tony Starr

I just saw the new Hulk movie a couple of days ago. First off, i'd like to say that before actually seeing it, I realized that two of my favorite actors were going to be playing hero and villain. The idea of Norton and Roth squaring off against each other just made my expectations for the movie shoot up to almost Dark Knight levels. It could have been a blessing or it could have been a curse.
In reality, it was both. Even though I had no expectations on Leterrier's directing, the acting and overall theme of the movie was really good. It clearly was better than Ang Lee's. The problem with making movies with the Hulk was inherent in the character of the Hulk itself.
The Hulk is relatively a shallow character. He gets angry, he turns green, he smashes things. There's not much else to it really.
On the other hand, you can focus on Bruce Banner's persona who is a much deeper character on so many levels. The thing with that is - who's going to want to watch a movie that's 90% banner and 10% Hulk?
Anyway, I had a few ideas that could have added to the entertainment value - like an insane sex scene with Betty Ross (Banner pulling out just as he turns green completely!), the Hulk's Sonic Clap rips tanks (and people!) in half, Abomination getting bigger as he gets angrier and at the same time hooks himself up with abomination-grade military weapons!
Bottom line, I think the recent Hulk movie was as good as you can ever get to tell the story of Bruce Banner and the Incredible Hulk.
But why did it feel like the highlight of the movie was Tony Stark's appearance at the end?