The limits of reciprocal restriction

The whole basis of the legal argument FOR zoning is that while a property owner has been restricted from developing their own property, that very real loss is none the less compensated by others losing the same property rights--that zoning is a sort of 'reciprocal covenant' that the homeowner bough into by buying that property.  (Houston is useful, because rather than having zoning, they have a plenitude of explicit private covenants governing land use). 

Monster houses are an interesting case, as they certainly impose costs on their neighbors (loss of light, view, etc), but those costs aren't recognized as property rights (even if they do affect your property value). Which begs the questions: why aren't duplexes of similar size permitted? And the immediate response is one of parking. Not of the amount, per se, but of it's regulation. Existing owners want to mandate sufficient parking that there is no possibility that renters will compete with them for on-street parking. And so they demand absurd levels of parking (One stall per bedroom).  

Because one of the tacit covenants of suburbia concerns the use of the local 'commons', the public street. You are permitted to store vehicles on it, but not so many vehicles that it impairs others use. Informally, it gets regulated as "Don't park in front of my house". But the whole things runs on social sanction (as I've discussed elsewhere) and renters (demographically different from owners) simply can't be sanctioned effectively. And as a a landlord, if you write me about my tenants use of 'your parking', in front of 'your house', my recourse to an impolite letter is to simply ignore it--I can't be socially sanctioned either.  So when owners fight against rentals, they aren't irrational--they are fighting the collapse of their way of life, and the beach head of an invasion. Because once that dam breaks, opposition to additional rentals degrades. People learn rentals aren't so bad, renters don't care in the first place, and the truly implacable will move away.