Lyxen
Great Old One
Please don't project whatever issues you have with your own DMs on me. I'm not them.
I'm not the only one who has read "issues" about the way you stated applying: "My general policy is to kill familiars on sight anyway".
Some of us around here have a more nuanced approach, including discussing with the player, for example in session 0. Familiars are necessarily recognised on sight anyway, and sometimes the NPCs have better things to do, etc.