> Otherwise the unit can just be passed from friend to friend and never get back to market.

I'm not sure how this is unfair. Considering the way capital gains are taxed after the sale it seems like the grandfathered-in rent controls are just a lever at the opposite end of the spectrum. But of course, we don't want to give any levers to the poors so it has to go.

We can want to support the poor and also recognize that prior attempts have unintended consequences or are ineffective. In this case rent control seems to reduce housing stock. The solution may be building more units so regulation should focus on that.