Because if you pick the wrong one (it's not always an LLC), there can be undesirable tax benefits.

@Timothy Hero so because the value is under that amount, it's an undesirable lending?

Maybe I am paranoid but I like to drive by and see how things are going if I could.I only wished I would have bought a bunch of houses in Sellwood when it was considered undesirable. is it too late to do this at 54?

And you may be able to adjust the amount of other deductions that result in undesirable/inefficient tax losses - both in the current year and the past 3 years. 

Although HOA is undesirable in some ways, it also means no exterior or pool maintenance to coordinate and pay for.

Either it has been very poorly managed, the property is undesirable, or there is something else going on.  

However, from the resources I have read across the internet and here at biggerpockets, it seems that the politics (w/ condo boards, bank financing, reliance on other units) make it more of an undesirable property type for the rehabee.

The city can provide some nice opportunities but the good neighborhoods can be small and well defined.   2 blocks can mean the difference between a family area and a very undesirable area, that will have much lower rents and higher crime.  

Physical problems with the building or a bunch of undesirable tenants in the building.

It would be worth studying up on that technique.Because you know the area so well, presumably you have a solid understanding of which specific neighborhoods are most desirable (and un-desirable)--use that to zero in on properties in the most desirable areas.