If I recall correctly, it was mostly because of the 501c issue that this didn't happen. That's just the way I remember it though. As an organizer myself, I don't want to be responsible for collecting fees but it really isn't difficult to do if this was something we found legal to do with the 501c thing. Just collect it and when you write the check to KCBS after awards, you just add on the additional amounts for non-KCBS teams who competed and give the reps contact info you collected on the entry form.
I don't think I'd like to see membership required to compete. I think the better angle rather than forcing someone to join is to get new teams involved and show them the benefit of membership while they're at the contest. Reps should speak with all non-member head cooks and welcome them and show a KCBS presence. Give them a Bullsheet (which we need to constantly improve upon - I would love to discuss this issue in another thread), some coupons for BBQ related products and whatever else we can come up with to put our best foot forward in extending a welcome to non-member teams and, if they join, recognize them at awards ceremonies as a new KCBS member. Instead of force, why not persuade and then make them feel like a part of the family?
KCBS Member #14287