In regards to the BL, this is the same post that I posted to someone's thread that questioned the beef between the BL and nonBL communities
This situation is very simillar to what happened on YouTube not long ago in my opinion, with the response girls whom responded to major videos, talking about the video while being all revealing their cleavage or being lowkey sexual. Why bring this up? Because of one main reason, BL, as a genre, is an easy way to rake in views much like the content of those girls. The reasoning here is that, in today's media, BL is a very popular form of story telling, two boys being all love-dovey, awkward and possibly even quite sexual. Now, to each their own, but as there is a high demand for it, people tend to abuse this genre by making series with little to know story, mostly fan-service, as well as bursting it out quickly.
Now, don't get me wrong, BL stories done right, any story done right, deserves views, however, it is for the fact that the ones with little to know effort getting the most views that's riling up the non-BL readers and writers as they feel that they've been duped or played. The algorithm prioritizes the most viewed, liked, subbed and commented for trending and popular, so a new BL that shows 2 cute guys doing cute stuff will gather quite a multitude of these things due to the demand for it, overtaking others' work in the algorithm. It's the same as the aforementioned response girls, the more people that come for the boobs, the more likes and views they get, thus shooting them up in the algorithm.
Personally, I don't like BL, to each their own, but rather than complaining about it, I've been studying them. The ones that shoot up have "BL" on their icon, indicating that it is indeed one, thus making people click it on the homepage. Not many people advertise their BL comic on the forums, so it would make sense that they might be outsourcing their viewership from possibly personal websites or Tumblr. Each episode, when clicked, showcases a very stereotypical scenario of two bishonen men doing either cutesy couple things or sexual hot stuff that would leave a BL reader all satisfied, thus garnering the like/comment/sub without really taking in consideration the lack of a real/proper story.
Compare this to a comic that took years to make and lots of effort to gather an audience, the clique of the BL will always win. It'd be fine if one didn't affect the other, again, to each their own, but it all boils down to the algorithm and how, due to their popularity, BL stories tend to be more emphasized than non-BL content.
tl;dr: The algorithm sees that people [refer overly romanticized and objectified men over other content, hence publicizes it more.
Also, shameless plugin, check out Jim's Days if you're into a non-BL mystery comic