Nomesorah; they’re allowed their opinions and we’re allowed to indirectly kill them under normal circumstances.
Even now, we don’t mourn them and we daven 3x a day for Hashem to “utterly destroy them”, in birchas haminim, the blessing of the heretics, whether they’re respectful or not.
Reshoim we daven to do teshuva. Apikorsim we daven should be eternally condemned. Their evil is a very different sort.