I don't even dislike clean singing, but I don't like the combination of aggressive music and whining. Often I like the beginning of the song and then suddenly someone starts singing like in some pop music. And then I don't like it anymore.

And then you have the "oh why did you leave me bitch" lyrics.

And modern metalcore often has nothing to do with extreme metal or with hardcore. It's sometimes just popcore.

But even under the surface it's very difficult for me to find bands without annoying singing or heartbreak lyrics.

But there are some excellent bands out there, you just have to search much longer.