Glory holes seem to be a man's game - straight, bi, or gay. The first pictures I saw of the concept were B&W, from the 80s, published in Der Spiegel in the early 90s. Till then, the glory hole idea was not really clear, nor particularly erotic. The Spiegel picture showed a man pressed against a wall with holes, and it is pretty obvious his hard cock is being well serviced from the way he is arching against the wall, and holding on to a couple of other lower holes on the side to thrust his hard cock better. But this seemed to belong to the same past as erotic late 70s/early 80s hardcore porn. The idea of simply pleasuring someone without any other contact, and the thrill of surprise each time became a tempting thought over time.
I had spent a period between 14-18 jacking off to porn, from Playboy/Penthouse to hardcore, often with a best friend or sometimes with one of his friends too, though never touching each other (nor at the time, any desire to). I have occasionally jacked off over the years thinking about how hot it is to watch a hard cock being stroked as I stroke mine. My friend's cock was cut, maybe bigger than mine (both average enough), and definitely pinker and whiter than mine when hard. He stroked more of the length of his cock as he got harder, while I tended to stroke closer to the head of my cock the hotter I was. We would stroke ourselves, share magazines, and sometimes watch each other, neither openly nor furtively - sometimes the stroking is so good, there is no way to avoid looking, especially when stoned. Sex is pretty universal, whether stiff cock or glistening pussy. A hard cock being pleasured is something men enjoy - they want their hard cock to get off, and when hard enough, nothing matters but how good it is. Probably many men won't admit this, unless they are hard themselves, but simply cumming with no contact except the sexual is a temptation hard to pass up, which is why glory holes are unlikely to fall out of male fashion.
Porn shops with private videos have been around for decades - combined with a glory hole and some good dope, the idea of watching porn with the chance of sharing the experience offers much the same attraction as the old porn theaters - men getting off, alone or together. I have talked to enough women about this to think the idea of a glory hole is pretty one sided - simply cumming for its own sake seems something all the women I've met find very male, especially when your partner is competely unknown. Porn and dope is not so gender specific - there are women who definitely get off on it, in my enjoyable personal experience. But getting stoned and cumming watching video porn has been a long term habit of mine, with or without a woman. Until today, without a man, either.