You get 1 trouble tenant and all of a sudden few years worth of cash flow is exhausted (think of maintenance/repairs). 

One good example of this is that the new 74 (Independence Blvd) opened and suddenly Idlewild area exploded because there isn't one stoplight between uptown and Idlewild anymore.. it flows well, and we've seen prices triple in that area since 2011.

We suddenly were staring at an about-to-be vacant duplex.

Suddenly going from not paying your mortgage to paying your mortgage and an additional trustee payment can be a daunting task.

Suddenly, everyone could do it.

Apparently in PA, if a tenant brings bedbugs into an apt, for example, they've lived there a year and suddenly there is an infestation where none existed before, it's the tenant's job to get rid of them. 

Hmmm, my position that a single rental property – even a single-family – could be a TB isn’t sounding so “blindly optimistic” all of a sudden, is it?

How did that other investor all of a sudden that other investor know how to get in contact with your heir?

Now all of a sudden the total rent including the MTM is 1/3 of what we expected.

The median net worth of homeowners surged by an inflation-adjusted 15 percent from 2013 to 2016, according to the Fed, while renters actually became poorer over that time."