Maybe that is not a good rule and maybe the folks thinking it up don't know what they are talking about but...
If your main interest is to fly turbines at your field and there are homes nearby that could be impacted by a crash thus possibly loosing the right to fly turbines or worse yet the loss of the field ,maybe having more turbines being flown by people who are not faniliar with your field isn't in your best interest.

While I agree with the previous post that I feel more danger from inexperienced pilots with trainers than the usual turbine pilot, that danger is on the flightline. The speed of the turbines makes them more of a threat to the nearby homes and the increased chance of fire compounds that danger.

So is hosting a turbine event really in your best interest or would you rather keep turbine traffic to a minimum and enjoy being able to continue to fly them at your field? I have similar thoughts when I hear of the desire to buddy box turbines or seeing someone who has never flown a fast piston powered plane being coached on flying turbines. It all seems to me that some folks are not aware that they might be shooting themselves in the foot.