Telling others they don’t like how others look is right near the top on the scale of offensiveness. I had a partner who had had dreads for 25 years. I’m wasn’t a huge fan of her dreads because although I like the look, hers were somewhat annoying for me (scratchy, dread babies, me getting tangled). That said, I would hope I never tell any other person how to look. Hilarious when she was working, and someone would treat her badly due to their assumptions or prejudices, only to discover to their detriment she was very senior staff!
Dreadlocks are usually called dreads in NZ. My previous link mentions that some people call them locks, which seems inapproprate to me: kind of a confusing whitewashing denial of history.