I'll chime in to what I see how the differences came about... frankly, it was two different companies and with two very different career expectations which were merged together. If this sounds like an East vs. West thing, then I apologize in advance.
Under America West, being a FSA was not a real job... it did not pay well, but the benefits for part-time were good for pass travel and insurance. The Company did not want people to make a career of this position, and Doug Parker even said as such that he didn't want 15-year ramp agents. The East mentality amongst FSAs was that working for an airline was a plum job, especially back in the early 80s, and once one could get their foot in the door, people don't leave because the pay was good, pension benefits, plus the flight benefits. For West it was just a job, and for East it was a career. Therefore, the dedication to the union and solidarity were vastly different because of the views to the same job, and frankly, the hostility towards Management is not as pronounced.
On occaision, I speak with West co-workers/friends who have transferred out to CLT, ATL, PHL, DCA and RDU, which are mostly East operations, and they tell me the attitudes are completely different about their jobs and Management, in general. There may be an eventual change from the West towards the East view now that the job pays for more and people become more entreched in their long-term career, and they may care enough to keep their career instead of just a throw-out job until something better comes along.
So Hypothesizes Jester.