I didn't claim to "know which UI is superior for all people." If you look closely, you might see that I had included "to me." I did this on purpose to make sure nobody thought I was speaking for them. I am annoyed that you did so anyway.

My comment was an opportunity for people to disagree with me - what about the GPM UI do you find inferior to the Spotify one?

The fact that you suggested ignorance as one of the possible reasons for millions of people preferring Spotify over Google Music speaks quite a bit towards your view of how important your feelings are.

If I ask you "Hey, why would you ever prefer the shoes you like over mine? To me, it's an obvious choice. Is it just because you don't know any better?", would you interpret that as an honest question?