While I'm not an airline jock I would hate to be excluded as there are aspects which cover ALL aviation. Nor would I like to see excluded others who are not in the profession but have valuable imputs and insights to make. I recollect a poster on the subject of the application of computers in designs such as the Airbus giving an educational insight into computers and their workings though he had nothing to do with aviation personally. A great contribution to the discussion. Like westhawk have pondered the question at length and my humble offering is,
1. Charge a fee
2. Attached to the credit card details attach a scanned copy of licence, professional qualifaction etc to establish you are what you say you are
3. Fill out profile to reflect the facts rather than as a canvas to exercise creative abilities
4. On completion of above and Danny/Mods are satisfied as to the bona fides some obvious sign be given that the poster has "passed the test". What that may be only Danny/Webmaster would be able to decide what is feasable. I thought perhaps your posting "handle" could be put up in a different colour than the regular Royal Blue - change to red for example.
Of course it all takes administrative effort. It might then be possible to ascertain what credence to give to posts made. On the other hand if the airline boys are dead set on wanting their own sand pit where all are excluded go for it. Perhaps you need to hold a referendum Danny.