your tastes were not more "mainstream".
I just don't like much rock, especially heavy metal or the more angsty stuff. Folk rock can be fun, and the stuff they play at the open Mike night at my local is fun too, provided you can dance to it. There's a rock group called Deportivo that I don't mind however when I played it to friends who like heavy rock they didn't rate it at all.
Most pop music is just a rehash of something that came before and for a long time has had more to do with marketing than quality. If I hear chart music nowadays it all sounds the same. There are outliers with genuine talent like Amy Winehouse and Hamzo Bryn though.
The last (non-classical/jazz) concert I went to was Nosfell (who also does rock music nowadays) but isn't at all mainstream. The two before that were Manaam and Sinead O'Connor who were very mainstream.