Make the SSA Bronze Badge and Silver Distance leg an FAR requirement for the Sport and Private Pilot Glider Certificates. These are relatively easy to do and makes you a better soaring pilot.

You have a cross-country requirement for the Private Certificate in Airplanes, and there are many more of those flying around. Why not for Gliders?

People fear what they don't have experiences in. When you've done it to get the Certificate, it becomes a non-issue, and puts you well on the way to competition or just doing the cross-country for yourself.