What's something that you were surprised to find out a lot of people hate?

The ending of How I Met Your Mother. Like, it was certainly no cinematic masterpiece, but I felt like it was a very logical build-up and delivery. I don't get the impression that they really stretched the story for more seasons either (yes I know they did add more things to stretch it, I just mean I think it doesn't show story-wise). But even a few days ago I saw people complaining about how bad the ending was, and it's a rhetoric I see almost every time the show is mentioned. And, again, it is not a cinematic masterpiece by any stretch, but I wouldn't expect that from a sitcom anyway.