less hate towards those who own several houses

There wasn't hate, period. I find it a foreign and even anachronistic mindset, I'd sooner expect people here to be simply jealous of those better-off. Also, owning several houses, not just two, could be problematic, the govt would probably try to nationalise some of them, at the very least in the early period.

I don't know the details of how it was all managed, housing wasn't definitely guaranteed (SFRY had a rapid urbanisation of the population, and apparently it wasn't easy to meet the demand for new housing), but overall the rate of homelessness was quite low, in part also thanks to the culture that didn't mind large families living in a single house.