Back in 99 some Southwest guys were leaving for UAL, DAL, etc. Turns out to have been a poorly timed decision. I guess that makes current SWA guys, like me; a little leary of the 'grass is greener' mentality.
I don't subscribe to the 15 minutes quip. You know: FDX, UPS, and SWA are having ours now and we're at 14 and counting. Airlines are in general cyclical, especially hub and spoke legacies. But, I think that some have found a way to manage their revenue/system to make money in up and down economies. Hopefully, SWA continues to be one of those.
Although, if you don't see your current airine as a career/destination place; by all means, search around. In a way it is good, when management sees guys bailing, they might decide that a little more pay/benefits/scheduling is in order. I don't think SWA is at or near something like that, although B6 may be with their 190 rates. In the long run, it works for everyone involved, the guys that leave get to go to their 'dream' airline with the ________ (fill in your desire here: widebody, int'l, domestic, one plane type, training every 2 years for that ATP full of types, whatever) and the ones that stay end up benefiting from improved contracts down the road.
The underlying principle is that we all root for the home team. We like to believe that WE were smarter/luckier than the next guy; not that we're idiots for staying on at a place we enjoy working at. It is a little disheartening to see guys get the fdx/swa choice and seem to usually choose fdx, but that is life. I also knew guys that only applied to one airline, SWA, and wouldn't have stayed flying if not hired. I applied everywhere and SWA wasn't my first choice. Lucky for me I didn't get what I wanted but what I hope will be better in the long run.
It is a scary industry where our hard earned skills don't transfer due to the seniority system, good in many ways, but it makes the A or B choice all the more important/life changing. And the burned bridge you leave behind is sort of a bummer too, that is for sure.
Good luck. I think the posters that say ask your real life friends and see how really seems to be happier are right on.