Typically the leaks have been toilets which will constantly run and use water slowly.

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There are many potential downsides – dealing with vacancies, problematic tenants, maintenance expenses, and the proverbial call in the middle of the night to fix an overflowing toilet.

And why many scratch there head saying "well i don't get it, how do you fix a clogged toilet from the back a thousand miles away" and a few immediately get-it and say "yup, I want that". 

"Yeah, I'm just a guy like anyone else, so I have a private jet, forget the Lambo and solid gold toilet, whatever, there just things, I'm an average Joe who found out....". 

He must have a stack of JV agreements in the bathroom just in case he runs out of toilet paper. 

Let's say Person B sticks a travel size deodorant down your toilet and floods the residence while Person A is traveling for work.

Including a flat fee for utilities on top of rent will make the rent look higher and less attractive to potential residents and potentially cost you money if there is a toilet running or water wasting.

At one point a plumber checking a toilet leak identified subfloor damage requiring the bathroom floor to be taken up and repaired.

There's just too much damned inventory and too many people willing to price to the toilet to keep people in their places.