For example, I personally can’t listen to Guns and Roses without immediately thinking “that Axl sure is an asshole”, and that sours the entire experience.
Yes. You listen to music without knowing anything about who wrote it and you feel something. That feeling has nothing to do with the composer or performer. Now if you find out the composer/performer is a “bad” person, I would recommend not giving them any money that could contribute to them spreading their “bad stuff”. I’d still enjoy the music because your enjoyment isn’t furthering their bad agenda.
That’s fair, but could still be undermined depending on the content of the music itself - eg if the music was all about respect for women, and then it turned out the person singing was an exploitative abuser, then wouldn’t your feeling about the music still be coloured by that, because it’d now seem insincere?