While I agree with a lot of things you said I disagree with pushing boundaries.
People that are really interested in him will find a different topic to bond, it’s not like music is the only thing on earth.
Also it’s okay to be the fun break, it’s a chance to get feedback about that and realize you need to find a different social circle that fits better to your own life. Or figure you push your boundaries yourself if you really want to belong.
But nobody has to fit in everywhere and if his boundary is his taste in music then who are we to question that?