I think it sounds like canny ebay vendors covering all bases, and making sure all sectors of the market are catered for. Having said that, I lived in Brighton for many years, Britain's gay capital, and have many gay friends. I must say, I saw far more kilts being worn in all styles by gay men than on straight men, especially during gay pride. I think it can be a way to be masculine and slightly flamboyant for men of all persuasions, and perhaps part of its popularity in gay culture may owe something to its championing by Jean Paul Gaultier in the 90s.

Not being gay myself, this could all be nonsense! Perhaps one of Xmarks' gay members could put me straight (no pun intended!)