Wrote this on another thread, but it fits better here..
Of the SO's I know who joined Cathay with the intention of getting a base, the majority wished they'd put off joining until they had accumulated the qualifications for a DEFO based position, or that they could resign right now and rejoin as a DEFO on a base.
With the latter being an unnaceptable option to management, most guys are watching their basing prospects erode away right in front of their eyes. In fact, they'll most likely be making the bunk for the DEFO hired two years later who's now sitting on your base slot blocking it for the better part of your career. Stuck in the slowest lane, replaying the shallow and brutally misleading words of the Cathay's "career options" presentation during the final interview in your mind.
Seniority means nothing as you career choices are reduced to 1)FO on base until retirement or a 2)FC in Hong Kong until retirement. Neither requires seniority once on base, which will likely happen right after your wife has taken your kids and left you for a DEFO flying out of her hometown while you're trying to remember what blue sky and green grass looked like.
The full realization of all this is that Cathay don't fear a turnover of SO's. When an SO quits in frustration (and they do), there's another 10 waiting to take his place with their eyeshades firmly in place on until it's too late. And the circle repeats.