Now I'm an evil landlord who should work for free because housing is a human right. 

Unfortunately the vast majority of landlords do not screen very well and rarely understand human nature.

I let the numbers (and human nature)  speak for themselves. 

Always do the humane thing!  

All tenants should to be treated equally unfortunately that is not basic human nature.

Reach out to a few and find one who will take you under their wing.If you're feeling altruistic, another way to learn and get construction experience is to volunteer for non-profits like Habitat for Humanity.

There isn't even a thought or decision here... had they come to you with a heart tugging humanizing story at least there is a chance you might consider especially if you feel the circumstances extraordinary, or be upfront and honest about whatever hardship they are facing and perhaps you have a solution that works for everyone - but a threat? 

Reality is every group of humans has some bad actors.   

I contacted the Humane Society and the officer told me the dog was being neglected and abused. 

You can screen well, but as long as the human element is there, you could run into anything.