To answer the original question of why someone would bail for a company with a 6 year upgrade- they are worried about the existence of their current company. It may go the way of Comair. With so many regionals for carriers to pick from, mainline can choose to outsource to the cheapest one, or one with cash in the bank. The product they receive is very similar (one would hope a company with more money would have better mx). United dictates what UAX carriers do: when a second beverage service is required etc. Lets say in theory you got hired on to the bottom of a list where the upgrade time is predicted to be 3 years, but it lasts 2, you never upgrade, then you have to go to the bottom of the list at another regional unless the hiring at AA, DL and UA picks up to the point where they need certificated pilots with a pulse. Or, alternatively, you could hedge your bets by going to an airline that offers decent quality of life, financial stability with the chance of upgrading. Could the companies these people are leaving stay in business, sure, but lets look at Great Lakes as an example of why leave an airline for what you call a lateral move. At one point people could go to Lakes and expect a 6-9 month upgrade dependent on how much time they had going in, now Lakes is JR manning captains to the right seat with no upgrade in sight for new FOs. Guys go there get their 1000 TPIC and either get hired into a narrow body jet, or take the PIC to another regional for some jet time.