Why do people dislike YouTube videos?

I'm not talking about videos that are genuinely controversial, or there's something morally wrong with them. I'm talking about the fun lighthearted ones that may just not be your thing. I hardly ever dislike a video; if I dislike something I just don't engage with it. It feels kind of mean towards the person who made it, just because they probably put a lot of effort in, so I feel like the least I can do is just not give it a dislike.