Rob21,
Interesting point. I all my many years of transatlantic crossing it has always been difficult to get 2 particular carriers to talk on 123,45 on 128.95 to discuss anything pertinent, ie, turbulence, or levels they will be requesting for onward planning purposes.
Those carriers are Air France and Lufthansa.
Don't know why...and this is my personal experience only. I always thought it to be because I am a pom!