Long post! Sorry!
I've played the game a few times to go through all the various paths and what not, and I also find it impossible to hate the game as much as everyone else seems to at times. The combat was a lot more exciting, for me at least, than Origins was, but then, I'm no RPG purist or anything. I actually went through the entire game on nightmare as a rogue hawk using Varric, Isabela, and Anders as my main squad, which I enjoyed a lot because I didn't have to do the tired old Tank/Striker/Healer/Controller structure. Granted I did end up with that structure by the end simply by how I grew the characters. My Rogue was max defense, so essentially a tank, Anders healed, Varric controlled everything with that rain of arrows thing, and Isabela just killed anything she wanted. And it was really fun to try and figure that out.
Origins kind of had the same ability, but combat was just so flat for me, especially as a rogue. I guess it might have been better as a warrior, because slow cleaves and stuff would fit, but watching the same, slow backstab animation over and over was hardly fun.
And then of course, story was important to. I thought, and disagree if you would like, that Origin's story was just the absolute worst out of all Bioware games to date. Well Bioware RPGs anyway. Almost everything in it was cliche, and the few things that weren't (like the Qunari for example) were so sidelined they might as well have not been there at all. The characters were nice, but hardly anything inspired, except Sten, Shale, and I guess Wynne.
DA2 however actually tread new ground and wasn't afraid to like, do interesting stuff. The character interactions were touching beyond reason (ever tried hooking up with Aveline?). The story was ambitious (let's tell a fantasy set in just one location!) and isn't given a lot of credit for that, I think. It even had more to say with itself, the major conflicts being about some of the major issues debated today (immigration, gay rights). The romances were not my thing, but still interesting in that they followed paths that most romances in games don't really. Except for Merril, anyway. There was abuse, the reconciliation of said abuse, even Isabela's promiscuity has a realness to it not found in a lot of stories, game or otherwise. And I mean guys have you seen Varric's chest hair? Perfect game just from that.
The world became more unique and exciting, even if we had to see the same dungeon layout over and over. You guys played Skyrim? Everything in that game is copy paste if you think about it. Why were we mad here but not there? That's a sentiment I have about everything in DA2. People got mad about stuff that is present in a lot of other, "greater" games, and ignorant of the things that DA2 does differently, and does right.