Also adding to Enzo999 post. From the outside the selection process might look unfit for purpose and not providing the personalities one might want. However from the inside, comparing the different personalities encountered within the airline to those encountered within former airlines, the band of personalities seems to be much narrower with less extreme characters then experienced in those former airlines.
That does mean that unfortunately some good pilots don't make it through the selection process but I would argue that the overall selection process works. Also looking at the amount of pilots who end up failing their training after being selected there seems to be a fair argument to keep on selecting on personalities rather then piloting/learning ability, in the end of the day, apart from the FPP's, all going trough the selection have a pilot licence and should know how to fly airplanes, trying to change a personality on the other hand....