They don't enforce paying for the editor. Those users may or may not be actually paying. You're right that it does seem like they could afford more staff. But its also pretty clear the guy who created it wants to write code and not deal with the other parts of being a "company" (see lack of public responses/updates). He created it, so he can market it/develop it as he sees fit.

I admire what he's done, and respect his choice if he's really not expanding because he likes to code and doesn't want to deal with running a business. But I also now use Vim because I didn't trust Sublime's future.