> My understanding was that it was the tenant rights movement that killed SROs and boarding houses by making it practically impossible to keep them orderly, because it made eviction almost impossible and compliance with anti-discrimination laws presented too large a burden for low-cost housing.

You could also just as easily argue it was naive reliance on the market that led to this failure. It doesn't take much thought to come to the conclusion that this approach will never fully alleviate basic housing concerns.