If a glider pilot wants to fly in the vicinity of a published glider field, which sensible GA pilots do avoid, then I don't see much of a problem with remaining on the glider frequencies or non-radio operations.
However, if a glider pilot wants to venture further afield, I think for his own safety (and everyone else's) he needs to consider the bigger picture before he goes flying in cloud without advertising his presence to others.
"Problem then of course is that gliders then have to all carry radios that cost money, and they have to be powered etc etc."
I really don't consider this to be a valid argument these days.
A hand held ICOM transceiver with a rechargeable battery costs about the same as four fill-ups of a car petrol tank. A lightweight gel type motorcycle battery could be used to prolong the battery life for soaring or cross country flights, at very little weight penalty.
As the old saying goes, "If you think flight safety is expensive; just try having an accident!"
Fly safe!
