The problem for me with DA2 is how much hp the mobs have in relation to the damage the team is doing. The fights aren't even tough, I'd say most of the deaths in DA2 were caused by friendly fire.
I think that along with the waves mechanic was honestly just an attempt to pad out the game time. DAO is a loooong game. DA2 is less so, which is understandable considering the truncated production. DA2 was only about 70 hours for me as opposed to the well over 100 hours for a DAO playthrough, but I would have been more than okay with a 40 to 50 hour game with better designed encounters. I imagine BioWare / EA thought many of their fans might feel cheated, though.
This I think speaks a lot to the MMO-ification of CRPGs these days, just inflate your characters stats and then make the mob's hp goes up to match it, while the mechanics never really change. This was all I could think about with DA:Inquisition which was just "watching cooldowns the game".
DA:2 clearly was rushed out the door, (in traditional black isle fashion) but they still prioritized the story which is also what I prioritize in these games so I wasn't too bothered by lack luster combat or the reused dungeon assets.
I wouldn't say MMOs did that. It was happening before 99.
