Yaoi is NOT a sin

^
Yaoi isn't a sin, nor is shounen-ai...and neither is BL!!!
Some BL may not deal with traumatic and abusive themes correctly and romanticize things that shouldn't be romanticized.
But BL/Yaoi is not the only genre that does that.
There are some really good BL manga out there, too!!!!
And I think its fine to have gay ships in a shounen anime/manga as well.
Two men in a manga/ anime who are dating is NOT a sin. Nor is it to ship them.
It feels so sad to me because nobody ever calls yuri/shoujo-ai a sin or hetero ships in other manga genres a sin, so why is YAOI A SIN?

Here, I would like ask you what makes a good yaoi manga? And how it varies from a bad one!