We collectively decide what's ok or not. The market is man made, man regulated, if tomorrow we decide housing is a basic necessity we can change that
Meanwhile we let the Qataris &co buy flats in Europe capitals and keep them empty as investments vessels, I find that much more disgusting that "think of the investors =("
Again, how does the existence of investors making money by providing housing prevent you from providing housing at below market cost?
You'll find that it doesn't. That any such restrictions are political decisions not investor decisions.
Their existence in the market doesn't stop you from existing.