1 - it is too easy to be sued. Basically, one is a generator if he produced anything that is a hazardous substance and ends up at the Superfund site. This includes deli owners, pizza parlors, auto lube shops, printers, companies with septic tanks, school districts, municipalities, etc. etc. These cases can be costly to defend. These costs alone can run into the thousands of dollars per defendant, and they buy no peace whatsoever with that money.
Businesses often file insurance claims.
However, carriers have historically denied coverage, which again means hiring a lawyer to fight with an insurance company. And many liability policies written after 1986 do not cover pollution claims. Though this result is unlikely, it makes it difficult to negotiate fair settlements. In addition, liability is retroactive. Thus practices that are now illegal but were legal 40 years ago are subject to Superfund liability.