For us the break-in  risk, proximity to other properties and the tenants generally being high made it undesirable to have them there. 

Many companies require you to use their application forms (on-line or faxed/e-mailed), which we do and add our own supplemental pages for info they don't request but we want.Think about the qualities of a good tenant, what your criteria is, and design a process to weed out undesirables and look at credit, criminal landlord history.  

Obviously it's not worth this amount (after living in it for a month I felt it wasn't worth this much even without the repair issues, so you can understand there are a lot of other issues I haven't noted here that make it an undesirable residence - friends and family kept asking me why the heck I was paying so much). 

Or is there something about your properties that makes them undesirable to good tenants who have more options?

Renting to the older tenant means less turnover and no kids.And I disagree that smaller units are undesirable.  

Some people would be surprised at how effective a $25.00 application fee is at weeding out undesirables.

This also makes a older homes undesirable for the average home home buyer/renter.These are my opinions but hope they help to explain why I am still intrested in the SF area as an investment.

That's why for me California for me seems so undesirable for buy/hold investors (besides the fact that prices are way too high to cash flow unless its recession time 2008-2012)It kills me to hear how long it takes to evict someone in California.  

Are there ways to attract undesirable tenants?

In my observation, investors are not selling properties in Sioux Falls right now, unless they are undesirable.