This is a real issue in my community (as is the case of pretty much every community). All the older homeowners and younger/middle aged middle class yuppies love to talk about how they care for the housing crisis for us poorer youth, but then anytime a plan to address it comes up it's all "muh property values, muh investment". It should be obvious to anyone that for the price to go down for buyers, the sellers must sell for less but they all want to sell absurdly high and then buy another home for low.
And outlawing landlordry would just mean that former renters have to take out predatory mortgages from banks.
These problems get real easy to solve when you address them both at once though.