Seniority is a lifesaver, if you have it.Seniority that is!
Scenario 1- expanding airline, buggins turn + minimum competency requirements give you a quick command. Lots of recruitment boots you up the list quickly, more underneath=more protection from........
Scenario 2- contracting airline. Now come the redundancies, demotions, re-basings etc. How to choose? well LIFO is cold and fair, add to it the required 'extra factors' to make it legal (eg. if you have a disciplinary on your record you lose 18 month seniority) and it is, above all else, transparent.
Its not a perfect system (neither is democracy) and it does protect the very few incompetent pilots (shouldn't it be the training dept. dealing with these?) in any organisation, but the meritocracy whilst attractive to the young and ambitious, will turn and bite them big time when they are less young and redundancy time beckons.(and God forbid, in the bad books of management) Its only a matter of time before one of the major LoCo's fail.
I have seen a 'job at risk' letter in my post in the past and I can tell you I have never been more glad to be in a seniority based airline. Even though I was in the bottom 30 of the list. This comes down to self preservation not selfishness. If, as is happening at a UK airline at this time, you have the 'base is closed, you're all sacked' scenario, it doesn't matter how hot a pilot you are, you're still unemployed.
Beware of what you wish for, as you may be granted it.