Not sure what you are trying to point out here. I'm assuming these Western 727 captains were not scabbing by quiting and moving to UAL.
It is very smart to have enough cash saved up to be able to take advantage of another opportunity. Why? Because you may be furloughed or have your airline decare Ch 7 on you when aviation jobs are more scarce. If you leave as a Capt when opportunites around you are better then I count you as one smart cookie. If everyone around you gets the same idea it would be good to beat them to the punch. Seniority is everything

You also make room for someone else to upgrade.
We've seen a lot folks leave UAL in 2000-2002 for jobs at JetBlue. Call it what you will, but they are back to Captain again in this turbulent industry. This willingness to pick up and move has got to be a very tough mindset to cultivate. They had a well educated and disciplined approach to protecting their careers before they hit the 45-60 range. A tough, tough decision to make but one that MAY pay dividends.
These so called opportunities don't always work out as planned but you gotta do the best you can, right?