Can't personally say I was part of the Nala thing. I tried to get some context on this convo but I got lost halfway through, feels like the point kept getting shifted so I guess I'll put in my 2 cents as well. As far as furry is concerned I think most people got introduced to that through lola bunny, gardivoir, lopunny, krystal from star fox, or renamon from digimon, how far one trends into or away from the beast side of that from there I think is where you'll find most people stop at anthro and don't full trend into feral.
I can sorta see why human male + beast wouldn't appeal to people. I think women having more bestiality content, and accepted bestiality content at that, is because it's an easier turn-on for people when it's just "woman inserts oddly shaped or impossibly large thing into themselves." Hentai introduced me to stomach buldge and impossible fit stuff so tentacles and horse were just part of the deal with that, knotting I believe is just size again but with stretching width wise more than length wise and getting "stuck" is the thing there while stuff like lets say the feline "spiked dick" could easily be associated just as an intensely nubbed toy. Dudes on the other hand have just, what, stretching the beast or goin spelunking in something too big for you? I personally can't see the preference in appeal for a feral over an anthro aside from maybe size unless you want to get into intense detail about the different vaginal construction between beasts.
Centaurs and minotaur games and doujin exist if you wanna bring up the size thing, don't get me wrong, but that's accompanied by the reactions of the human half as well, female beasts just don't have enough of a reaction and when the kinda pseudo human psyche in a beast body happens it feels forced at least to me. Anthro just covers the beast part with a reasonable human element to it, if it's about the mating season or "heat" aspect then furry's and the kemonomimi genre already has that. if it's about certain idiosyncrasy's with them like snakes coiling around a partner for hours on end, then monster girls or scalies got 'em covered, they don't have to go seek out the snake from jungle book etc...
I don't think people can resonate enough with wanting to fuck a beast, fake or not, as much as they can relate to being the beast being driven by primal lust, or being the girl getting railed in those kinda works. As far as human dude + non-human most people'll probably stop at just ears and tail then that filters into monster girls, that filters into furrys, and that filters further into the drops of full feral, there's just a seemingly smaller market for it.
Ultimately, yea, porn is nothing but fiction and people can be into any kind of taboo or fetish or kink, Knocking on others because of what they like is kinda moot when none of it's real and everyone's just venting lust. except for scat, I will never understand or play devils advocate for that. I can't say I understand NTR's popularity either though I can admit to liking the Netori side of it but being put off by the Netorare side of it
I got lost writing this much like how I got lost reading the convo for an attempt at context so it goes everywhere and nowhere, I don't even know if I hit the correct topics but I've written too much to delete it.