Originally Posted by Chris P. Bacon

When determining whether something is right or wrong for an organization it's best to assess whether that activity is consistent with their mission statement.

Looking at the AMA's mission statement:

"The Academy of Model Aeronautics is a world-class association of modelers organized for the purpose of promotion, development, education, advancement, and safeguarding of modeling activities.

The Academy provides leadership, organization, competition, communication, protection, representation, recognition, education, and scientific/technical development to modelers."

I can't help but notice their attendance would be considered "promotion" and "safeguarding of modeling activities" which is certainly consistent with their mission statement.