That's because they know deep, deep down that men generally prefer to commit to women who have a lower n count so they try to shame their friends and non friends to be as slutty as them. Shaming them and calling them boring, envisioning a sad and cringe future for them, calling them losers and such.

Doing that will bring those low n count women to their own level. This makes them be worried less of their sluttiness.

Being promiscuous will lead to more sadness.