My point was you can’t compare the two groups objectively if you only like one of them.
I feel like this almost makes sense but doesn’t. You’re making it sound like if you don’t like a band you have a bias against them, but that’s not necessarily the case. There are different levels of liking. What if I don’t like Green Day and only kind of like The Cars? Does that make me unobjective? Or can’t I say The Cars are objectively more worth liking than Green Day? What if I don’t like either of them? Does that mean I can’t compare objectively? Or maybe I can because they’re on the same level for me? But they can’t be on the same level or I wouldn’t be saying one is better than the other, right?
Music is simply too subjective - there’s no right or wrong here. And comparing too fairly different bands means even more cause for subjectivity.