It's all of the grift/graft reasons other people have written, but there are also a type of American that reads only this shit. They probably don't even read them, they just stack up until they die and their kids have to figure out what to do with them.

My partner volunteers at a charity thrift shop in the book section. They sometimes get shipments of books that were rejected by Goodwill because they're unmarketable. They get this kind of right wing political slop, which ends up in a dumpster.