I don't blame the airlines for running cadet schemes. Who would want to hire pretend GA pilots who whinge and whine about what they call "clapped out bugsmaashers" and the terrible bosses who won't buy jets for them to fly. Too many have very negative attitudes and only intend to stay for a short priod.
The flood of these negative GA pilots has killed the goose that laid the golden egg.
If you want a good aviation job you need a sensible, positive attitude, and a long term committment.
If you don't, you won't.