Well the defining word is 'owner'. As a site owner, I'd say that they are pretty much at liberty to stick up what they want. They can make rules up as they see fit too. If they say no-one else can have a certain logo except them, that's their prerogative. If they want to advertise a business on their 'own' site, the one they monitor, maintain, design etc what **** thinks they should also pay for that privilege?
This whole thing has been borne out of a member disagreeing with something that apparently one of the 'owners' did. So!!!! IT'S THEIR SITE! It isn't a co-operative, a committee (thank god!), a gang, club or charity. It isn't even a democracy!
To be honest I don't know why the owners have wasted any more of their time over this. It's dead simple, if as a member you don't like something about the way the site is run, then p*ss off and start your own one with your own rules!!!!