Hello Pace
Glider are not equipped for IFR flight (and never have been to my knowledge). Gliders have been equipped for IMC flight for most of the last century. And the ANO, the type certificate, and operational regulations permit this.
Airliners have been traditionally kept safe from collision (although not always successfully) by segregation and control. The result is that enormous areas of the air are sterilised for the exclusive use of IFR aircraft, and strict separation apropriate for the days of poor or non-existent primary radar exists.
If airliners now wish to fly full of passengers in the open FIR, and require other aircraft to fit expensive equipment, then they might consider investing in the safety of their passengers.
And I suspect it will be an airliner hitting a glider rather than the other way round..............