You underestimate the ability of a large media company to squash innovation and morale. They might get outside investment so they can iterate harder/better/faster but Advance wants to hold onto this goldmine.

From http://www.betabeat.com/2011/09/06/a-startup-is-reborn-reddi...:

Greater independence will mean reddit can go to a new board, which includes reddit OG Alexix Ohanian, who had been serving as an “advisor,” as well as representatives from Conde and Advance, with proposals instead of jockeying within Conde’s budget. Reddit doesn’t plan to seek outside funding at this time, Mr. Martin said, but it’s not out of the question. “It’s a lot more more of a startup,” he said. “It’s able to happen faster with less overhead.”