Yeah, it matters bc switch couples (seke) are so rare in regular bl. Typicaly, uke/neko/catchers are receivers that have that stereotypical feminine outlook, submissive and emotional feel and the seme/tachi/pitchers are supposed to be all manly and dominant--even though both people have a penis, that fact always seems irrelevant for the uke bc they orgasm with their prostate. Ukes are always emasculated like that, it seems. Anyway, I'm not sure how it works with bara bl.
uh yeah idk i think forcing the stereotype of bottoms always being feminine is kinda weird tbh. (obviously ik there are feminine bottoms irl but usually the ones in bl are written by women which gives me a weird vibe) i also dont see the need for female readers to relate to the bottom. like idk i dont think many readers actually self insert or whatever when they read bl. if anything i imagine pegging masc dudes rather than getting fucked by them but i digress.
Why do people care about who's uke and seme? It's like asking who's "the girl" and "the man", but they are both male so it doesn't really matter, or does it? ╮( ̄▽ ̄)╭