I have a BTL because if I didn't I'd be trying to live on the state pension. My BTL enables me to have a roof over my head, which I can heat in the winter and gives me some spare money so I don't have the worry of how I'm going to live into my old age - I'm nearly 70 now and don't have the energy to continue working at my age. It doesn't keep me in untold wealth.
What exactly do you think would happen OP if all the 'evil' BTL landlords disappeared overnight. Do you really think that all the people who currently cannot afford to buy their own homes would somehow miraculously manage to scrape together a deposit and get a mortgage? Of course they wouldn't. So where would they be living? With their parents? On the street? In council housing? Well that's not going to work, is it?
Of course BTL is an investment, many people invest money in various ways, BTL is just one way.
Not all the rent I take goes into my pocket. The house needs to be maintained, repairs made, LL insurance has to be paid and I have to pay tax on my earnings.
The current tenants in my house could easily afford to buy their own home but at the moment it doesn't suit them to because they might not be staying in this country long term. They are neither poor not exploited by me. They earn a hell of a lot more than I do.
Might also add that they are the third tenants I've had. The first couple sub let and left the house needing a lot of work to get it back to a rentable quality and the second couple didn't pay any rent for the six months it took to evict them through the courts. They left the house in an even worse state than the first couple.
These BTL bashing posts pop up every so often, with their sweeping statements and naivety but nobody on any of them has yet come up with a sensible system to replace private LLs. But I be interested to know when someone does.