In short, otome.
A lot of the time, BL relationships are presented like "normal" heteronormative relationships anyway, just with both people being guys. One guy is so feminised, I wonder why they bother with the gay angle to begin with. Both works often invoke the same/similar tropes- particularly the prevalence of rape culture. It's like the creators can't be bothered learning or can't empathise with how a "normal" guy/guy relationship works, so they feminise one guy a lot to make things easier, or create the uke just so that the female readers can insert themselves in the uke's POV better. Doujinshi and more... "amateur" fan fiction are particularly bad with this, warping their chosen character's out of shape and then into an uke to facilitate the plot and chosen pairing. An uke is rarely any different or better than the protagonists you see in otome games and shoujo manga, to be honest.
I also find it hard to believe that everyone in a mafia is gay, everyone in a high school is gay, everyone in an idol group is gay, every guy in Shingeki no Kyojin doujinshi are secretly or not-so-secretly gay, etc. There's rarely any prominent or meaningful female characters. It's one thing to make a game homosocial, but another to make everyone the protagonist meet "turn gay/bi" or just happen to be all gay. Even so, it's fiction and I'm all for everyone safely enjoying their fantasies, so it's not like it really matters.
At least, these are my observations from the BL works I've been exposed to.
I'm not a gay man, so perhaps I'm speaking out of turn... but I have quite a few homosexual friends, and while that won't substitute first-hand experience, I can confidently say that many BL works (and yuri, for that matter, though yuri aimed for older girls tends to be more realistic) don't accurately depict a "real/normal" MxM relationship. BL perpetuates some truly dumb stereotypes about homosexual men and their relationships, though mainstream media is only a bit better in some instances.
There's a lot of interesting points of discussion in a topic like this, but my post has already gotten pretty long, so for now, I'll leave it here.
TL;DR: I hardly see the difference between the two other than the genders of those involved, but I prefer otome since it caters much more to my personal tastes.