That's the problem. These exemptions were put in to help protect the internet when it was a lot smaller. And also you need protections to protect small companies who don't have the resources to survive and police user-uploaded content.
But Google make tens of billions in profit a year. They're not some poor start-up anymore. They just want to make some extra profits, by avoiding their responsibilities. Facebook are the same.
They're moving a bit now, because public pressure is starting to tell. It would almost certainly be better if regulation was light, and then well funded organisations behaved responsibly. It'll be interesting to see what happens.