Serious question - what rules in 5e encourage bad player behaviour?

Not one person ever: “There is no song about Oath of Devotion Paladins”

… this list contains like 3 items phrased differently ~7 times each.

“This person had a family/friends” “This person was supporting someone else” “This person liked their pets”

repeat …

I think the issue is that horny is the only option my dude.

The problem isnt ‘i want vampires that are horny’ but ‘I want there to be only vampires that are horny’

It’s not about someone getting what they want, it is about wanting other people not to get things you dont want.