The problem is that many gliders use a collision avoidance system that is very good indeed. Sadly it is also completely incompatible with the industry standard of transponders (mode c/s) and TCAS which in turn is only mandatory for bigger airplanes (something like 19 passenger seats, 5.6t?).
I know that some operators of small commercial planes install
FLARM in addition to normal transponders, especially those operating in areas with high glider traffic density.
The problem i see with FLARM is the incompatibily problem with the existing system used in most powered aircrafts. Two coexisting incompatible products are not a good idea at all, especially if it leads to a false sense of safety in both communities. The one thing to take into account is that commercial aviation allways has the bigger lobby and more power inside the legislation system to change the system to accomodate its needs. That doesn't mean that GA has just to roll over and take it as it comes, but a less heated discussion is often a better way to achieve results.