I think it might be one of those movies were the action pay-off just kills off all the momentum the movie built up in terms of character building, etc.
I think the best difference is comparing The Incredible Hulk with The Avengers. While the last hour or so of The Avengers was also pretty much all-out action, it also managed to round off the character stories like Stark learning to be a team player, Banner to accept the Hulk, Black Widow getting over her fears, etc. There was character progression in the battle, which gave some meaning to it. In The Incredible Hulk we see Banner realize he could 'aim' the Hulk, which is the end of his character progression and the fight with the Abomination happens. It's twenty minutes of pure brawling but it really doesn't matter what happens in the fight because the character arc is already complete.
There's a reason why the hero always has some mid-fight realization before finishing the fight. If he had the realization before the fight then he would have nothing to gain from the fight anymore, which makes it just an empty punchfest.