Went through this when my (then teenaged) daughter was into K-Pop. You can guess what I thought of it. After we'd gone back and forth on her tastes vs mine, I told her, "This is just how it's supposed to be: my parents thought my music sucked, I think your music sucks, and one day you might have kids -- and you'll think their music sucks. It's one of those circles of life."

(Added content: after she'd asked me to watch some K-Pop videos, which seem to exclusively feature boys/young men who dance while lipsyncing, I had her watch . this. Her eyes got a bit wide when she saw people playing actual instruments.