The county and towns generally have a balancing act (besides the fact that most decent business people won’t run for city councils or county supervisors) between how much the property is with and the clean up costs if they get it back. Many times the person had very little money and the city/county knows that anything they do under forced cleanup will sit there until the property is sold to clear the lien and sometimes the property is more costly to clean up that what they would receive.
I know a bank that had a loan on a property and it became a dump site. The bank released the mortgage and internally deemed it an unsecured loan so they would not get the property back due to clean up costs and potential “hazardous” issues.
The most ridiculous thing about this is that our garbage service out here is very cheap, like $100ish per year. I told my wife we could just pay for their garbage service if we knew they'd actually put it out by the road.