It is great that clubs and individuals form relationship with ATC and voluntarily follow procedures, use transponders etc. but the system is only as strong as its weakest link. As long as folks allow themselves to fly without transponders at busy areas, a bad accident may happen.
We didn't hear until now if this midair was avoided thanks to see and avoid or the glider had a transponder which triggered a TCAS alert which saved the day. Will be good to know, and we should know by now.

Ramy