Cant speak for yuri but as a fujo i feel like alot of yaoi/bl is for focused on being sensual and pretty than actually horny. Thats thankfully not always the case but alot of the time dicks are very censored or undetailed, the whole “yaoi hole” thing, theres a focus on fingering and facial expressions, and the guys can be pretty androgynous. That mixed with the fact that most bl is more focused on in depth romance between established characters i can see why a lesbian wouldnt mind it. I like the pretty androgynous guys and tasteful eroticism but i sometimes have to look for bara or more western stuff if i want something explicitly horny