Yeah that's my take on this sort of thing.
Like it's gross - a lot of anime tropes are - and not at all the sort of thing I'd care for myself in a story or IRL...but it's fiction. It's a victimless crime at most.
And if people overreact to fiction too much and let it influence them to do strange things IRL, then that's a problem with their way of thinking.
That said I've never gotten the appeal of siscons and brocons and such. At the absolute most it can be amusing for a gag, but only if I mentally pretend they're not related.