I think it's an interesting moral question: How much are you responsible for someone else's failure to plan ahead or foresee consequences? What are the consequences if we make you responsible for other people for their entire life just because you have some economic interaction with them?

I think if you make renting someone an apartment a lifelong obligation to provide them with housing at approximately that cost then only a fool would ever rent out an apartment. The supply of apartments to rent would go to approximately 0. One strange consequence of this would be that the price of housing would plummet as a result as all the landlords left the market. When you went to buy a condo, instead of competing with landlords and money launderers you would only be bidding against other people who want to live in the apartment. I saw this first hand at the GHI housing co-op in Maryland, buying a unit there was dramatically below market cost because they did not allow anyone to live in units apart from owners.