This doesn't sound like someone who bought 4x houses and became a slum lord.

Renting out a home you own is a normal part of home ownership. You might move to another city, care for your elderly parents, or move in with a spouse.

Its easy to say "oh well hurry durr you should sell because charging rent is unethical", but in practice no one would actually sell in these circumstances for that reason, if it were contrary to their interests.

This has been happening since the first troglodite laid on some straw and called it a bed. Renting for a few years is not everything thats wrong with the property market.