How is the potential problem of housing future people an argument for a policy that allows kicking out existing owners?
They don't seem to me related. This is about the rights of ownership.
The problems you mention stem from various "kick out" policies that are essentially forced assets transfer and artificial scarcity policies to inflate prices (difficulty for new housing, one family houses, height of buildings, devaluation of residential areas by bad policing etc)
Housing prices are results of specific policies, and people's ownership rights are protected in western societies.