I actually think it is more complicated these days and the OP is asking a valid question, albeit perhaps without realising why.
As a cadet you are arguably at your most valuable in todays recruitment market. Many airlines would prefer to recruit cadets due to cost considerations. Just look at what is happening at British Airways, where experienced pilots are swimming in the holding pool while cadets join the airline and today a new cadet scheme was launched.
Making your first move in aviation the right one is becoming increasingly important in my view, since should you be made redundant at some point, the next lot of cadets behind you will be competing for the jobs, and guess what, in many cases, they'll probably win.