For me it totally depends what I went into it expecting. For instance I don't mind fanservice, even excessive fanservice because sometime I fanservicey comedy is just fun, as long as they're up front about it. If you're going to go "this is a super deep dark story we want you to take it seriously but also omg look boobs for no reason" it's not going to work. For instance Cross Ange is a pile of beautifully animated and voiced fanservicey trash but if you know that from the very start and doesn't pretend to be otherwise and if you can tolerate that there's actually something of a half decent plot under there. But if I watched Handshakers because it was billed as much the same team as K which I adore (the decline after S1 of that should have clued me into how this was going to go) but I couldn't get passed episode 1 even after several attempts, the animation was an awfully obvious 3d, the boobs were huge, the jiggle physics were awful and was the girl making sex noises in battle really necessary in a show you're trying to tell me is serious and threatening?
Although the pettiest reason is probably because my friend insisted something was "the best show ever" in all seriousness and then that she'd "never connected to a character like this before" about the villain in all seriousness, without a hint of irony or joke, and then said she couldn't be friends with anyone who didn't like the show it was so important to her. It was already dragging as a show, but it had potential so I was sticking, but after that I dropped it so fast.