Another point of view. I have been one of those "buddies" "let" in for free. To keep it in the theater perspective, I helped clean and or touch up the film before the show, and donate during other normal operations. Then get yelled at for being a freeloader.
A big difference though, If I brought a camera into a theater and photographed the movie, that is illegal; and I am on private property. Photographing or videoing the railroad is not illegal or against any policies if done correctly.
This can be a lose lose for all. I think the best way is to sell tickets for a ride on the train, and have someone volunteer to take donations at different stops for the people chasing the train. Anyone who is there for the operation of a rotary run that is not a paying customer would have had to hear about it from somewhere. They would also know that it is not cheap or free to run. Also, if the railroad were to push its sales department, I'm sure it could sell some kind of advertisement or movie rights like the beer commercials of the 70's, or the recent Seth McFarlane movie. It doesn't have to rely solely on the rail fans.
I for one love the Rio Grande, and its predecessors continuing to run on old ROW's. I also do not make excesses of extra money. Some talk of $500 or $1,000 like it comes weekly. While others, this is the annual budget for a vacation. Keep in mind that those you complain about are also those shoulders you stand on to see as far as you do!
Casey