For the same reason I've always posed;—the notion of any type of filter such as this being innocent also presents the prose of a lie. Unless it's purely an option to simply turn romances off.
It presents the possibility of an exclusive nature—and nothing about this game is exclusive as there's an opening for everyone.
If you were to present a filter of the sorts, you risk pampering to the potential bigotry that will most likely incur as a result. I've been over on the Steam forum, and some of the people there are, to put it gently, disgusting with their behavior toward the LGBTQ+ community, to the extent of making light the idea of killing every individual that identified as such in the same writ or chagrin that is meant to be cruel and in gest.
If not for that simple, vitriolic element, I would personally be all for an option like this. But that fact alone that I frequently see Transphobic, Homophobic, and Misogynous comments regularly being made elsewhere is what makes it a hard "no" from me.
I understand there are respectful, simple folk who want it. They in-fact deserve to have the option, but you can see the dilemma here.
