I once read a theory which asusred that it was a "safe" way for young girls to explore themes like love and sexuality while maintaining a distance, until they could understand their own bodies better.
I don't know how much water it might hold, and how many cases that might apply to, but it's true that, waaaaaaay back in the day I was a fan of yaoi and now... it simply doesn't click with me anymore.
It's also worthy of mention that many, way too many hetero pairing in fiction are based on abuse of any kind (from the man and from the woman). It's is from the man, it's in many cases about the woman's personal struggle to stop the domestic violence against her. If it's from the woman, it's about the man's plight when seeing himself in an infernal divorce with false accusations. It's a bit tiring to not being able to find almost any character in american media (and, by cultural contamination, in the rest of western media) who is happily married or that, at the very least, has the drive to stay in a relationship, whatever form it might take, long enough to count aniversaries with two hands.
And I shit you not, many an ultra feminist movement and their polar opposite twin (but basically the same), MGTOW, use that very same media of disaster marriages and voilence to nitpick scenes and made their respective cases against the other gender. Because we all know that Hollywood is an accurate image of our society
Oh, and don't forget the "romance" movies on which the female acts as a doormat as long as the male lead is rich/immortal and handsome
I don't know, yaoi's conflict is almost always about the pairing surviving societal conventions and their own demons, thus they might be seen in a much favorable light, maybe? At least one member of the couple is not always trying to dry the other from their money, or try to kill each other.
(Sorry if I spoke out of turn with this one. My knowledge of yaoi media is pretty limited and surely dated. I'm sure those themes are adressed by yaoi and yuri media, but I was talking about it in very broad strokes).