Most of these monster girls want to *marry* you... Or at least, trap you forever, and never let you go. (Or if you are female, turn you into one of them.) Maybe dating is fairly easy, but staying faithful seems hard. Cheaters seem to be dealt with rather harshly, as well...
I think the reason why they reccomend fleeing is that these blurbs are meant to be Public Service Announcements, or something. The government of the place wants to keep humans mating with humans so the species doesn't go extinct, and they don't expect everyone to be an accomplished adventurer.