People talk about things they like, partially because they trust you to open up about them and partially because they're trying to relate. It's not really the same as responding to bland food, (unless bland food is your special interest) what's your favourite things, and how would you feel if someone said something derogatory or negative after you talk about them? (Not saying you did that, just that's a better evocation of the relative emotions)

Think of it like in improv theatre. The rule of the stage in improv is, you always say, yes and.... Because without saying yes and.. the conversation / performance dies. It also puts all the weight on the other person to think of and introduce a new subject topic, after you disparaged their last effort (sometimes that's how they feel). Probably the shortest way to explain it is you need to be careful not to yuck someone's yum.

It's not really about the topic, it's about the person bringing it to you.

Personally I like the challenge that it is to say something nice about something I don't like. For instance, I mostly share your opinion on music, but I could find a fun fact to pull out about a particular musician, I could find a particular talented musician to talk about, a childhood memory, something short if you don't want to continue the conversation much, something long if you've found something good to branch off into. Or instead just say "cool, what do you think about *insert favourite music here".

Personally for the music, I talk about Woking in a pub when I was younger and it ruining the songs for me, as they were played on repeat, every night. (Even though I never had a proclivity towards them)

Just think about something that gives them something to talk about after, or ask them a question about it, as it's about getting to know them. People want to know you care about what they like, not necessarily care about the things they like too. And you want to continue the conversation, what keeps it flowing.