What is it people hate so much about "punk rockers"?

I see this girl sitting on a curb, smoking a cigar. She was wearing leather clothing with patches and buttons of some sort, a red mohawk hairstyle, covered in tattoos and piercings. So what right? But then another women was walking down the sidewalk talking with someone else, and she turned and looked, just looked, at this cigar smoker and said to her friend, in a soft whisper, "I don't like her". What is it you don't like exactly? I see this women, looks like any one else to me, I don't get it. I see a cop or fireman, I don't say I dislike them, just because.