Checking out music-theory on the side to learn about what you are listening to and how to explain it is a bit different IMO to people who went to music-school and stuff; at least in sweden, I think they have a tendency to be very snobby towards stuff that is simple in terms of chord-progressions, musicianship etc. and that comes with the knowledge. For the record, I have read a lot of music theory too even if it was a long time ago (when I played bass and a little piano in my mid-late teens) and I don't think it has had a negative effect on me but i cannot lie, I was a bit snobby too for a while even if I personally never ahd any problems with Hip-Hop, it was just so far removed.

I also think a knowledge about theory (actually, they don't have to know theory for this but still, an increased technical skill can also fuck up here) can affect artists badly in the sense that it leads to an "awareness" about what they are doing (and by extension, what they should not do) which IMO is often actually a bad thing in music as weird as that may seem, especially if you are doing/writing simple music and your theoretical knowledge is more than functional. It takes a certain type of discipline here which theoretically untrained songwriters/musicians/whatever don't even need to bother with (the types of discipline they need to work on is a different one)