What is the allure of a duplex such as this one that doesn't make any sense numbers-wise (as far as I can see)?

[Jeremy Hale]

I see a lot of duplexes like this one:

http://www.realtor.com/realestateandhomes-detail/5...

While that is a bit of an extreme example (a lot of them will pull ~1600 in rent), there are still a *ton* of duplexes out here that are nearly 300k and make ~.005% in rent. Perhaps it's not a good deal, yet people are buying them - what am I missing? Are these people praying for massive appreciation gains? The house I linked in particular doesn't even cashflow $0.. it would cost you money to own it.