You could point out that someone will own these homes and manage them, and if they are your friends and family - don't they think you are a decent guy? You don't get to define what exists in the world, there is a large population of renters - its a fact, someone will own, manage and maintain the properties. Why not you?
If not you? who?
And are those other owners going to be better for the tenants and the community than you? if so, why?
Forget the why's of renting: its a reality.
Forget the why's of income inequality - its not up to you.
You have recognized reality and chosen your place in it.
I'm not a real estate investor because dealing with tenants sounds like more trouble than its worth - its a choice, I know I'm giving up money and returns. I am able to meet my goals without it. I have utmost respect for you and what you are doing and hope it goes awesome for you. I think you earn your gains with either work or risk. I'm not willing to do the work or take the risk, I certainly believe you deserve the returns you get for doing both.