The pipes slowly corrode, you have buildup on the inside which restricts flow to the point where you don't have enough pressure at the faucets, they develop pin holes, shut off valves start leaking or seize up, so when you have to shut off water in an emergency, you can't and you are causing more damage.

While I agree with you to a degree, @Adam Bartomeo, I have a different viewpoint.One bad tenant can cause all sorts of problems for several good tenants. 

@Zachary Overstreet The Real Estate Crash of 2008-2010 caused real estate prices to crash across the country - but didn't affect rent amounts.

(That's satisfying.)Cost for owning and maintaining the site for an entire year are (for us) less than the cost of a single booking so as far as I'm concerned, the experiment has already paid itself off+.

As far as I was concerned, it was absolutely worth paying QC for 30 minutes to an hour (if more was needed) to make things right.

I now support directly with time (we volunteer quite a bit for women/children and veteran causes) and support $ debt buy-offs like school lunches and medical debt and being the Quartermaster (treasurer) of my VFW post I get to help lead our local veteran relief efforts. 

Since the neighborhood isn't the best, I'm concerned the value of the home won't go up over the years as it would in a better neighborhood.Does anyone have experience doing BRRRR's in C or D neighborhoods that can give some advice?

Let them know that issues concerning code violations are of concern; cosmetic issues are not. 

Sellers need to price competitively, prepare carefully, and address potential buyer concerns before listing.

Even though you didn’t install the door or cause the issue, the property (and everything in it) became your responsibility the day you closed.