White None,
Have you read the letter? I have. If there is no threat of follow up action, then there is no point in writing or signing the letter. Either you think safety is compromised at CX as a result of a fatigue and inexperience nexus or you don't. If those whom signed the letter believe what is contained on its pages, how can they not be willing to resign? It's like Yammer. The words are all well and good; but if you're not willing to do anything about it, it's really just a waste of time.
Taken a step further, a line captain can ensure safety on his/her particular flights by assessing his/her own fatigue, enquiring about that of the crew, and ensuring the alertness levels are sufficient to offset any inexperience or recency concerns. A C&Ter has no such ability. They either sign the license or not. Once signed to the line, the C&Ter has no control over what happens. If s/he truly believes we are in danger (I believe we are), then s/he should be unwilling to sign the licenses. Since that goes with the territory of being a C&Ter, then s/he should resign from training. The math is pretty simple in my mind.
I'm not writing this from an industrial stance, but from the opinion that we will have an accident before long. It is very likely that some combination of fatigue and crew experience will be causal. We are rapidly devolving into an airline with cockpit experience no different than that of China Airlines or Asiana. I think that is a poor choice by management. CX has always been a first world, western airline based in Hong Kong. I believe there is value in that, but it's changing.