Would you be offended if someone described a car as being a bit pikey? You know, if it looks like it was built in a shed and held together with cable ties? When people describe pikey mods, they're not suggesting that the car is in fact an Irish traveller with awful hair and aggressive tendencies. The same way that when people describe a bgw, they're not suggesting that it shops in Topman and is covered in fake tan. It's just a different use of the word.