My partner does not think so because it is in an undesirable area, and, although property values are on the rise, this neighborhood will be the first to take the hit and go back downward when/if the market tanks again. 

Even further south in Colo Springs, quad's come on the market for 399K ask needing rehab work in undesirable parts of town and get snatched up.

A better strategy is to make it undesirable to rent for one night by increasing the admin costs associated with a single night stay.

Middle to Upper Class individuals are moving into areas in Brooklyn that a few short years ago were absolutely undesirable for the reason you mentioned.I would be lying to you if the idea of relocating altogether hasn't crossed my mind....multiple timed.

I made the mistake of purchasing in an undesirable neighborhood.

Several things are red flags: the low purchase price, especially for a duplex, almost certainly means one or more of several things: it is in an undesirable neighborhood and it will be difficult to manage, they didn't do much on the rehab and it will have some very significant differed maintenance, it will be very difficult to exit without a loss because it won't appreciate. 

I do this with undesirables moving in to my units.If you can serve the notice the police will arrest him for trespassing.

But when I compare this investment versus trying to house hack in an undesirable neighborhood of Brooklyn it seems like a no-brainer. 

Buy undesirable wetlands, marshes, and DEC protected lands that could be sold for pennies on the dollar.  

Investing in "undesirable" areas is never wise... regardless of price.