I confess I'm playing devil's advocate here a bit, as I do understand the point that you're making.
But - if the house isn't bought by another landlord, but bought by someone that's going to live in it, where did that person live before?
Obviously if it's a young couple buying their first home, they've likely lived at home, but some people may be able to buy, if as a PP said, the increased housing stock reduced prices, whereas they might have been renting previously.
The property that they were previously renting now becomes available.
As I say, I'm playing devil's advocate because I also understand that unfortunately that reduced housing stock for rental properties will ultimately put the rents up even further.
There is an overall reduction in the quality of "society" though I think. So many more people just don't give a shit any more about anyone other than themselves. And even then, they don't even seem to give a shit about themselves, given the state that some people are happy to live in.
My DPs have always rented and have looked after their property like it was their own. The properties have always looked better when they move out than when they move in.
My DH has a rental property and the state that the house has been left in on check out can be awful.
The worst was a single guy that lived there that never reported any issues to the property manager but when we go in there realised that the bath seal had gone and the shower had been leaking everywhere. It had ruined the bathroom floor, the kitchen ceiling and, talking with the neighbour, had even seeped into their house and made their house smell damp too. He left a load of crap behind that he didn't want to bother clearing and he obviously had never cleaned the place since the day he moved in.
As a PP also said, when you run a normal business, if you have to borrow money to grow or support the business, you can get tax deductions on your costs, including the loan interest. When you're a landlord you only get very limited reductions in your tax. I know it's supposed to put off landlords to give more people the opportunity to own their own home, but it all fails miserably when the house prices remain too high for people to buy them. So you end up with fed up landlords that are being over-taxed and fed up tenants that are paying too much for rent.
No idea what the solution is though...