It's generally the other way around.
Touché
Actually, it's only the other way around in yaoi, which is a very small sub genre of manga so it isn't in any way general. I understand that it seems general since this is a manga site that is mostly dedicated to BL, but if you consider the fact that to a majority of the otaku world, yaoi is not a favorite and even avoided in many cases, you can see how it is not a general cliché in manga. And yes, manga besides yaoi is relevant because the manga the comment is on is not yaoi.
In your defense, it is a commonly used trope in yaoi to "turn a straight guy gay" and I for one prefer when the characters were originally gay. But when it's done in yaoi, there isn't the underlying notion that being gay or straight is wrong. I dislike the "turn a gay person straight" trope more, simply because it feels like an attack on homosexuality. As if they aren't really gay, just confused, and they only need to meet the right person so that they can see that they aren't really gay. That's how I see it anyway :)
Interesting. I've honestly never seen that trope before. Only heard assholes say stuff like that to me and others in real life, lol.
I guess you're lucky that you've been able to avoid such unpleasantries at least in the fictional world. Sad that the real world isn't as kind to you.
Then again, she did say that she never got a chance to figure out her sexuality. So who knows? Maybe she's bi or even a pan.
"I was never interested in guys to begin with. Not that my heart ever fluttered for a girl... I simply assumed that I was a bit different. But there was never an opportunity for me to find out my sexual preference. Until that day..."
http://www.mangago.zone/read-manga/why_did_men_stop_wearing_high_heels/mf/manga/why_did_men_stop_wearing_high_heels/c032/pg-2/
She doesn't like guys, she's made it very clear throughout the manga. She even likes another girl in current time but has been afraid to do anything because she thinks her sexuality is something to be scorned until the recent breakthrough with her brother.
Back off, she's gay. ( •⌒• )
I hate when mangakas make a gay character and then make a straight person "fix" them.