Did these "many people" ever look at the offerings of Khan academy? That's not academic stuff. And Coursera lacks serious cohesion and supervision. Those are two necessary (but not sufficient) conditions.
But university is about more than learning some formula by heart or reading a book. You need to get an understanding of the context of the theories, the process of discovery, and be guided through the history and current practices. It's not for everyone, but it's certainly not something an online course can provide.
Who writes these free courses anyway?