When you look at the link from Likalixer it is clear that the issue isn't that much the Buy To Let system but the fact that landlords don't have to ensure that their houses meet certain criteria. So they get the maximum profit with the minimum investment.
I'm at loss as to how you can have some properties to rent if you don't have people owning them. These people will have to have raised the money one way or the other so unless you are happy to have only the 10% richest people owning properties that are there to rent, I'm not sure how you can avoid that.
I laso have an issue with this idea that it's wrong for landlord to have the rental income as their main income. Looking at properties like this IS taking time and effort, more if you actually do it well.
For comparaison, there are other coutries where the BTL system is present. France is one of them. But you don't have the issues youy find here re how high rents are because the rules for rental are completely different (You can't kick someone out your the property even if they don't pay, price increase are regulated etc etc).
the real issue is the one raised by Sorry. The general level of house prices is crazy and people do carry on playing on that, even with their main house, selling and buying a bigger house etc... to make a profit. All in the hope that once they retire they will be able to sell it for a big profit which will be their retirement pot.
Eg, in some areas where I live, people who have grown up there can't find places to buy. They are on low income (countryside) but most houses are bouht by people has a second house. usually by people from 'down south' with higher wages. now there are few houses left for the 'locals' who ae running the economy of the place.
So similar problems than the ones raised for the BLT but no renting in sight...
Maybe having a second home should also be frown upon?