Because of the scale and reach of the operation. The convict profited from his enterprise. Not everyone across our country thinks that dealing hard drugs on a large scale is so innocent. It was a nationwide operation.
But he wasn't dealing hard drugs. He made a website. Should ISPs get two life sentences because they built a network which enabled users to sell drugs online? Should the creators of Reddit or Craigslist get two life sentences because users probably sell drugs using their platforms? He might not be a saint, but he doesn't deserve two life sentences.