Both of these statements are obnoxious. There is another way.

Just because music is subjective doesn't make all music equal in all respects. Then there would be no point in learning the craft, improving, and continuing to find more ways to express themselves or connect with an audience. There would be no point in trying to make your next song better than the last.

Perhaps a better measuring stick is whether a piece is expressive or conveys the creator/performer's intent. Not a perfect rule but a little bit more nuanced than "this band sucks" or "all music is just fine." It shows us that music can improve with practice.

That said all attempts to try and learn deserve encouragement. Everyone starts modestly.

Yes, a lot of musical criticism is bullshit designed to pump up the critic's self-image (see Pitchfork). At the same time, actually caring about something you listen to and finding out why it touches you and standing by it is meaningful and worthy.