Nymphs outside of botany are comparable to stray dogs.
They're animals and should be afforded rights accordingly (as AI I sometimes inform sec of "animal cruelty" going on), if they behave badly (which they often do), they become pests.
I don't mind nymphs, sometimes even make friends with them IC, but most of the time they just screw around in an antaggy way, the last round I played as QM (my new favourite job) I kept passing out from the latest shit virus, a nymph thought it would be funny to go around stripping people, when I quite reasonably responding by telling first to bugger off and secondly by throwing it away, it then started bashing my head in with an oxygen tank until a friendly sec borg batoned it.
Another time I had my traitor round ruined when a nymph kept unhandcuffing my targets.
The point is, Nymphs, most of the time in my experience, behave like antags/pests then people complain when they get treated as such.
They are technically animals after all, non crew certainly, killing them should be an IC choice with possible IC consequences whilst abusing being one really needs closer Admin scrutiny IMO.