The idea that moving from airline to airline will require some "explaining" at your dream-job interview is a myth.
I have done more lateral job-hopping than ANY of you. (Chautauqua to AirTran BACK to Chautauqua to USAir to PSA to Comair to a Part 91 corp.)
I've never had to offer any more detailed a response then, "Based upon the (domicile, work-rules, equipment, lifestyle, __(insert reason here)__, I made the best decision I could at the time with the information available." I don't think that anyone ever looked down upon me for going back to Chautauqua, for example. (Except maybe for Polar
On the contrary, on a number of occasions people have said something to the effect of, "It must have taken guts to go back to the bottom of the list...".
The introduction of the "big" regional jet...transition jet...replacement jet... narrowbody jet... how about just "airplane"... has had the result of fewer net major airline jobs available. Everything being equal when every person who walks through the door has a CRJ/ERJ type, a few thousand hours PIC turbine, etc... there is very little to differentiate one candidate from another. There will be those among the masses who will, for no reasons other than the cruel hand of fate, be relegated to a regional airline career.
So why would you stay someplace where you are unhappy...where pay and work-rules, and lifestyle are such that you can not imagine raising a family? There is some merit to the PIC turbine argument... but once you get that magic 1000 I don't think an interviewer in the world would question your decision to better yourself.
Now don't get me wrong -- i'm not talking about going to Republic because they fly an E170 and it has engines under the wings and looks wicked cool! No, that's SJS.
I'm talking about choosing a company where a combination of domicile (or ease of commute), pay, and work rules are such that you believe you can make a career at that company if that becomes your fate.
I still know several pilots who I was hired at Chautauqua with (the first time) in 1996. They live in beautiful houses, have wonderful families, and plenty of time at home. If they never get hired by a major -- they've lost nothing.
Don't buy the hype. If you find yourself in a dead end job -- change jobs. Slavery was abolished by the 13th ammendment. I don't feel much empathy to people who gripe about their job 24/7 but are waiting for the (SWA...UPS...FedEx...JetBlue(really?)) ship to come in.