I don't pay much attention to the townies that the game generates and I really don't have my sims associate with them (is that bad?).
I've had none of my sims that are in households get culled. If I see a townie that interests me, I will move them in to a house and have them marked as played even if I dont play them in my rotation. (I may down the road so I save them from the culling beast)
I've had relationship culling since the patch and have had to reintroduce sims several times. I got fed up and installed Neia's no relationship culling mod. So far, so good.
But yes, it needs fixing.