It's a reflection of societal norms and expectations...
...regarding members of the same sex. Being a product of the environment in which I was raised, which was likely similar to many people's, I have come to accept many of the viewpoints that, admittedly, could stem from a bit of homophobia. But all of us see it everyday, and I'm not necessarily saying it's right, but again, it's what people expect, and it reaches far more areas than tickling when it comes to what most people are comfortable seeing two women do together but would be uneasy, even appalled, at the sight of two men doing the same thing. Women can dance together at clubs, go to a public restroom together, hold each other's hands when they talk (even if they're merely friends), and obviously can tickle one another. I'll freely admit that the idea of two men doing any of those aforementioned things together does not interest me at all or even strike me as appropriate, and on this site I would never tickle another man in cyberplay, want another man to tickle me, and certainly not watch a stream or clip that involved two men tickling each other. This is merely a product of how I was raised and what I've come to feel as an adult, and I don't judge anyone with interests in men tickling each other. But since it's the case that that's what a society in which men still "make most of the rules" dictates, hardly any m/m videos or clips or stories will surface; it isn't creepy or gross necessarily by nature, just not a big draw or sell because not many prefer to see it. Luckilly, this forum seems to cater to literally every tickling preference or taste imaginable, and hopefully all members feel comfortable exploring, even expressing, their interests regardless of how uncommon they may be, and I'm glad it exists.