i watched Hellraiser: Bloodline four times just to understand 1: how is this possible other people actually like it, 2: why on earth someone would create such abomination 
Now that's dedication lol 
I was a big Total War fan. I played the games from the original Rome and loved them all up to Rome 2. I have sunk 182 hours into that game playing different factions trying to find something to like about it but it just bores me silly. So yeah people can plow a large amount of hours into a game hoping to find something to like.
I loved the original Rome Total War!! I also liked RTW2 though, but less because of the combat and more because of the RPG aspects lol 
Still, there's a small difference here. It's not that comparable to DAI given the massive divergence in how different playthroughs are. In DAI you're progressing a single character, exploring the world, playing combat, and experiencing the story. The 100 hours you spend finishing the game are all tied together in that one character.
I'm going on assumptions here based on personal experience, but you probably cycled through factions playing each for a few hours or so (with some more than others) in order to figure out which faction you enjoy. If you stuck around for more than a few hours then you may have enjoyed something until you realized that it wasn't as good as you thought it was. Then you rerolled til you thoroughly exhausted all the interesting options
So a more proper comparison would be you playing every race and class combination in DAI to figure out one that would captivate you in the story and finding that none of them fit the bill. If you dislike the combat, the story, the characters etc... then you just don't continue any of the playthroughs and you're done with the game unless you really are a masochist.
I actually did the same thing with Civilization Beyond Earth. Granted it was around 40 hours or so, but I just couldn't get into it as much as Civilization 5. The issue was that I enjoyed roleplaying my civilizations as much as I could according to their historical equivalents and that substantially increased the game lifetime for me. There are only 3 factions in Beyond Earth and they were all sci-fi. The game was fun and I tried all the factions, but if I was going to sink in that many hours playing a strategy game it might as well be Civ5 with all the amazingly fun features introduced throughout the DLC cycle and such. Perhaps when all DLC is released, I'll return to Beyond Earth but that won't be a for a while.
You underestimate the irrational nature of gamers.
