I haven't personally been a landlord, but I'm on the board of our HOA and there are a few homeowners in our complex that rent their townhouses to Section 8 applicants.
I also questioned this the first time someone said they were working with Section 8 for their rental, and what I was told is that it's actually a good way to rent your home because you're guaranteed the portion of the rent the government is paying (as well as the HOA dues), and that there are very strict guidelines the renters have to follow. The downside is that there are also strict guidelines the homeowner has to follow as far as allowing inspections, having safety features in the home, etc. I would imagine if the renter was violating a part of the lease agreement that justified eviction, you would get support from the Section 8 department because they wouldn't want to be paying rent for someone who isn't holding up their end of the legal agreement.
One of my next door neighbors is a Section 8 renter, and she's one of the best renters that's lived there - always courteous, friendly, keeps her unit clean, etc. And she's lived there for a few years now, so I would assume she pays her portion of the rent on time.