First of all, an airline has to assess the abilities of a candidate regarding a position.
For us the required qualities are obvious. By going through psychological questionnaire, the psy get a first picture.
The psychotechnics test are also an excellent clue to figure out the learning abilities of a wannabee. In our modern world where competition prevails, where fuel cost is increasing day by day, airlines do not want to spend extra money on training so they want to mesure how fast a candidate can learn, adapt himself to new and unexpected situation: a sim check shows the flying skills and level of a pilot but does not show how long it took him to reach this level!
Team work is essential in our job: between cockpit crew, cabin crew, ground staff , ATC, management, pax..etc Group exercices are made for this purpose:
How an individual interacts with others while dealing with problems solving, enigmas etc... It is a very cheap way for airline selection (much cheaper than sim!!) and a most companies have integrated the group exercise as a part of their selection for management positions (we are managers!).
At last but not least, an individual meeting with the psy is part of some airline interview: Does the candidate fit the position, what is is motivation, does he know the airline and company he is applying for, what is his background, studies...etc
You must not see the whole process as a way to sack or eliminate you!!
If a company is recruiting, that means that they need you!!
Take this as a way to show your motivation, your abilities, your will to join the airline, to be a plus and of course your love of flying.....
Good luck