It's an interesting & quite layered question. I've been trying to think of a band/artist who's objectively rubbish on every level - but I don't have a single example. I can think of any number of bands who have members with no discernible ability - oddly it's usually the vocalist, and even more oddly (or is it?) you can be confident that if they didn't have that vocalist, you'd never have heard of them. As examples I give you Liam Gallagher, Axl Rose, Ian Brown - terrible, terrible nails-on-blackboard 'singers' but all absolutely central to their bands' success, despite the fact you're left thinking the only reason they got to be in their bands in the first place was because it was their van or their PA or something...
I think I grew out of the 'that's rubbish because I don't like/get it' mindset by the time I hit my 20s, and while there's a lot of music across all genres that I don't like (I'm a prog fan who thinks Dream Theater are utter dogsh!t, for example) I think I can be analytical enough to appreciate (maybe not the right word) why something works, and usually how, even if I hate it.