I apologize in advance for the wall of text but I felt compelled to dispel a serious misunderstandings of the Kink community and by extension Fetlife from your comment here (though I think getting into the idiosyncrasies of the kinky community and lifestyle might be a wee bit too far off the rails/topic for the discussion of tumblr providing a platform for those interested in adult content).

Sure, while Fetlife might not be a "blogging" platform like Tumblr or WordPress is, the functionality of the site as a community shouldn't be dismissed as a viable alternative for tumblr refugees just because it isn't dedicated to periodical columns the way WordPress is even while the platform has a versatile and quite heavily used blogging feature.

It also trends strongly towards kink

Yes. It does. That's the point. They advertise it as such or try to convince you of anything otherwise. . They don't sell you anything else. That's entirely who the community was built for, it's the entire purpose of the site.

The very first thing you see when you go to the website is:

FetLife is the Social Network for the BDSM, Fetish & Kinky Community.

So yes. That's exactly the point of the site. But I also made sure to add, that among other things, the site is a pretty good and welcoming community for artists of many types: painters, drawers, photographers, writers, it can be many things to many people who want to trade in, and interact with 'adult content' despite the headline viewers see before even logging in or creating an account of their own.

But again, as I said in another comment in this subthread: kink != sex and to be earnest in discussing the affair, it's probably helpful to divorce one from the idea that kinky material == sexy material. Some people find pleasure-and it doesn't have to be sexual pleasure, it could entirely be psychosomatic in controlling what another says and does as a dom or domme. Conflating the two only sets back the entire discussion IMO.

Further, this part has me raising an eyebrow and sorry if I've missed your point but:

and white heteronormative sex, which excludes a huge portion of the Tumblr lgbtq+ spectrum.

How?

Not to be a contrarian on the subject, but as a person of color, my own experiences with the site can be surmised the way a lot of people surmise their experiences with many sites like reddit, twitter, et al: pick the communities/subgroups you want to interact with, ignore those you don't.

So how does Fetlife as a platform "trend towards" white heteronormative sex? Just curious because the platform, best I can tell over the last five years as an active member allows the user to choose what groups they involve themselves with, and what people they involve themselves with and which groups they don't. If you're a person of color, looking to interact with polyamorous people who enjoy rope play, there's a good chance a group exists for it, and if not there is nothing stopping you from creating that.

If you're a white person who wants to interact with non-poly people and are looking for just plain-jane sex with other white people, there are groups for that too.

Best I can tell, Fetlife enables you as a user to find and interact with all sorts of individuals who fit your specific theme/motif of "pleasure" however you define it, and places no limitations on those who exist outside of however we decide to define "normative" on a given day.

Is it possible the experience you speak of has less to do with the platform and more the groups you've chosen to subscribe to and the people you've chosen to interact with?