Sure, a source code repository is an essential tool. But if you have a company that has a room (or several rooms) full of developers that work on a product, the expertise (arguably, the whole raison d'être) of that company is in the things that only they do. The tools are necessary, but you don't want every developer to have to devote any more time than is necessary to learning/using a tool.

I'm not arguing against source control, I'm arguing against a tool that so complicated and is obviously so hard to master might work against us as much as it work for us.