> It seems unreasonable to me unless there is some reasonable justification as to why 4 is legal but 5 is illegal.

It's not a set number...Municipalities can set this as low as 2 or as high as whatever.

As to why - go and ask them? Presumably it's what the local voters wanted, or at least the most vocal ones that cared to show up to council meetings and such.

> I'm all for regulation that makes sense. Like mandating safe or sustainable building materials, clean water, carbon taxes, emission standards in cars, and so on. It just feels like 95% of the laws are just pointless stuff like "put a employees must wash hands sign in every bathroom"

Chesterton's Fence.