Going through the comments, I think the major factor some people fail to see is that the number of people who've…
saying a show is overrated means you think the show dont deserve the like it gets from people, thus it means you think people who enjoy it so much is wrong, so that means you think other people's opinion that is different from your opinion is invalid, that's why i never take people who says something is overrated seriously, as what they means by that is trashing other people's opinion, SO it's not an opinion about the show, but rather about people who watch the show, so that means you are judging other people negatively, and that's something i dont like, an example of having an opinion about a show, would be "i dont really like this drama" and saying "i dont like it as much as other people" since what you are saying focus on the show, not the score it got from other people