There would be no disincentive from the company to train everyone on everything because there's the wage bill doesn't go up as a result. All the acrimony over training slots would be gone, all the crap everyone has to go through in the fallout of training selections. The taking up of union time in following up on those issues.
There wouldn't be a sly reason for a manager to punish someone who made a them angry or look stupid once upon a time - and we all work with people who has been punished by never receiving training ever again. In fact I dare say that is endemic within Qantas.
Just a few thoughts.