Why is the single player getting railed on so hard?
Also, the quick time events are not that bad. I don't see anything wrong with them at all. They are in plenty of other games but I can't say I have heard a review for another game that has denounced them so heavily.
About the game being "scripted", yes it leads you to the next objective and there are a couple times where if you don't get a certain weapon they tell you to you die, but seriously, the protagonist is part of a U.S. Marine squad (the other protagonist is part of another type of unit). There aren't that many shooters I can think of that aren't linear in some way, except for maybe the first half of Crysis 1. This game (most of it) definitely isn't a hallway shooter so I don't get why people are so disappointed with it.
I didn't find the dialogue (most of it is in the cutscenes) that bad at all. There was nothing that jumped out at me as being really cheesy or lame.
I felt like the story was actually pretty good. It wasn't extremely complicated and wasn't the most original, but it presented the story from different perspectives, gave the player some emotional ties to some characters and had a couple revealing moments that were really interesting/moving.