Quark is a businessman and he has employees. The basic idea has been that Ferengi are a bunch of privateers, not people who are docile enough to work in gigantic bureaucratic structures.
The part of the Ferengi government we see, the Grand Nagus, is as capitalist as it gets. Note that colonizing has often been done by governments. Take a look at what the Chinese are currently doing in Africa, that's only possible with a strong autocratic government (which is basically the same as a large corporation). Hard to picture Ferengi being engaged in such activity.