Those are very misleading scams or they have other issues they don't tell you about. I tell people that come into my office who are looking for the $1 homes that if that were true (and I throw down a $100 bill) that I would own 100 of them. Obviously it is not true in the sense you are thinking it is.
You might find a dump for $1 but it also comes with tax liens totaling $20,000. Or it has been condemned and needs $100,000 to fix it enough to be out of condemnation. That is the truth about $1 homes.