I'm from a time where if you were enough of a weirdo to have found skateboarding and taken your licks you were in, skin colour, gender, haircut, whatever.
Issues come from groups of males left alone with a lack of female influence on their environment, it changes behaviour, not just skateboarders but any group of "lads". The more insular and singular the demographic the more likely to be prejudiced to anything outside that norm.
As progressive as we like to think we are, operating outside social convention and being rule breakers, the similarity in attitude to females is on a par with a amateur local soccer team's drunken stag doo to Magaluf.