Roughly speaking that's correct. The GPL isn't hostile to paid means of distributing a program, but it's hostile to distributing binaries while deliberately obstructing access to source-code. [0]
An aside in the interests of precision: the GPL doesn't force 'everyone' to publish their source. If your fork is private and is never distributed at all, you aren't obligated to make your source-code available, and you don't even need to tell anyone you have your own fork. The Affero GPL licence differs from the standard GPL, on this point.
