That is a red flag for certain and asking about music is a important factor in dating. If you don't like the same type of music odds are not in favor of making a connection.
You'll never be happy with that person if you don't like the same music. Like I would never date anyone who likes Country Music. That is a hard stop for me as it says that you have no taste and like things that are bland and boring. I'm more of an Alterative Rock type of person and sought connections with those who like that style of music. Being Gen X that wasn't hard to find.
Never be happy? What a completely moronic take. Honestly I think you should keep avoiding people who don't like the same music as you, they're probably better off without you around them.
I don't know that it's that big a factor, people can connect in different ways, but it can certainly be a spring board for getting to know someone and make a connection.