So basically porn is everywhere..especially and that's why question. Why it is getting so normalize that wherever you look, it's non-con and porn? Is it so hard to write a piece of fiction without them?
What amazed me and made me feel shameful equally that most of the authors/writers are Women. Because of this, I've seen many men saying 'Women fetishize rpe'
Yah tho if you connect the pattern, it's to milk the trend, take the "Transmigrated as the duke's daughter" type of story and look how many story does this title relates to, you might not know which "Transmigration" story I'm saying (I will talk about the trend and somehow this is happening to BL, Idk about Yuri)
So it's the same to Yaoi and if someone is like really genius enough to write such peak green flag stories then a lot of authors might as well milk that for monetary
The rape arc, especially men raping men, doesn't change unless society changes. It especially shows in media written by women.
In Japan you could write gay men more positive when they finally started to get more accepting, and it did show in yaoi how they got past most of the rape arc - and authors could write more positive stuff.
Similar timeline with FL in shoujos etc. being 14 years old and sexualize, thou that has been a bit slower change, but started before laws changed to 16 being age of consent.
The reason why Korean BL manhwa is stuck men raping men arc, because men abusing their partners aka women is common and normal. So the rape in BL is basically outlet, and minorities who suffer from it will be damned. Because Korean society isn't getting better even for the women, so there is no room to other minority problems and the men raping men arc will not end unless the society/culture starting to changes.
And all of this is very simplified version explaining it.
But in short:
Japanese media women were also trying to change things better to everyone, while toeing the line what they can write. Also, when you changed things to be a bit more global, it would sell better outside Japan too just when manga is getting really popular in western countries, so a little bit of capitalism.
In Korean media it's pretty much only outlet for women to have revenge as authors and reader, rape is culturally more normal in the domestic life and hyper capitalism there will use anything to make money.

Why literally every new yaoi is nothing more than a p*rnhwa?