Is being a landlord immoral?

This might not be the place for this discussion but as I thinking to buy a property to rent out within the future. I thought I'd ask the question.

I see a lot of comments demonising and hating land lords for profiting off the misery and suffering of others (not my words, saw them on a recent post). Usually because the renters are in a position where they can't afford to save for a house. This additional cost slows down the process of them getting the funds for a house and we have a snake eating it's tail.

To use Kant's words: we should use persons as an end, not merely as a means.

By renting out a home to a person we are using them as a means for our profit. I've gone several layers deep into this and I'll cut it short so I don't ramble.

My question to you is do you think being a land lord is ethical? And can it be more ethical based on how you treat your tenants? What other investments do you make if you can't justify being a land lord?