This situation is more complicated than just "Congress imposes copyright law upon the public", though. Generally speaking, the people at large have consistently failed to demonstrate any kind of consensus opinion about copyright law, much less a democratic mandate that would clearly indicate to Congress what to do. But they do care very deeply about ensuring the economy continues to grow, especially with somewhat unfair international competition... and the easiest way to do that is to continue to push copyright maximalism.

Yes, individual Americans will get harmed by, say, anticircumvention law, copyright trolling operations, or automated content ID systems. But nobody gets outraged about that in large enough numbers. They do get outraged, however, when they hear about "China stealing our valuable intellectual property" or somesuch. So the message Congress ultimately hears is, "More please!"