Because? Seeing US/non-US comments I think that is your local quirk.
Nobody discusses porn video content and actors themselves, except “bald guy from brazzers” and other folklore. Otherwise it is the same technology, much better and advanced than e.g. youtube freezing crapware show. Idk why someone should not discuss that. Because if you know that it means you watch porn?
Talking about video infrastructure that happens to be on a porn site, sure whatever.
But, lots of people are uncomfortable talking about sex at work. I'm just trying to do my job, I don't want to have to talk with you about whether I know who "bald guy from Brazzers" is, why I do or dont, which porn sites I go to etc. My sex life, porn consumption or lack thereof is none of my co-workers' business, and keeping your nose out of other people's is a good default. Especially if you have GLBTQ+ coworkers, you can easily ostracize them.
In my experience, once sex and porn start trickling into the conversation, conversations seem to devolve into fratboy territory. Just keep it away from me. I literally quit my last job because of the fratboy vibe, my boss asked me if my wife's pregnancy "made her horny" and that was the last straw.
I think there's a vast difference between discussing porn and discussing the technical details of porn websites. I'd never discuss the former at work but I have discussed the latter, albeit only with colleagues I know well and when it was directly relevant to technical problems we were discussing. Also not in communal areas.
And when part of your team's responsibility is fighting to keep pornography off your website? Snicker like a child when it inevitably comes up and go "so unprofessional!"? Or act like an adult?