You are not dealing with a state that will say "teehee, we have no proof of the data that's going through, oh well!". Anyone found operating one of these gateways will just end up being beaten with a wrench, and traffic logged further on. Considering this, it's overall safer to not go through a central gateway, and to have as many possible connections going through. Hell, even PCs stored in weird places, in government offices, just to make the signal to noise ratio even worse.

A gateway is a single, big ass signal that says "come murder me".