I work on a hundred of those every year at a non-profit shop that's dedicated to keeping bikes out of landfills, and getting them to people who need them.
The typical case is a gummed up trigger shifter and at least one non-working brake. A volunteer will spend an hour on it and get it back on the road. There are several trailer parks and low income apartment complexes in the area. We keep recycling bikes through those areas. Folks need them to get to work, for the kids to ride to school.
I usually replace the quick release set post clamp with a bolt, to make it slightly harder to steal.