I read stuff like this and it makes me realize that I would never, ever want to be in the business of being a landlord.
I am in the landlord business. Its not that bad.
The key is operating like any other business. Always treat tenants fairly and consistently, don't allow the units to fall into disrepair, have a good management company to interface with the tenants, and don't be adverse to paying an experienced landlord/tenant attorney to get the uncomfortable part of the business done efficiently and without drama.
It also helps if the rental units aren't in the same neighborhood where you live.