It could be the grass is always greener ....
I have only been actively aero-commuting for the last 3 years. I have had a chance to try out various LLC and legacy carriers, and to be honest, it is a love-hate relationship with most of them.

Right now Delta is treating me well. My opinion will probably alter a little once the weather really starts hitting Atlanta. I understand continental is short airplanes, and the load factors are higher than they would like (makes IRROPS difficult to handle). I know they are addressing that. It doesn't help my immediate situation.

Frontier was great when they flew the routes and times I needed. Now that they cut back, I couldn't fly them if i wanted to.

JetBlue is a real enigma for me. They were the first airline I started flying with, but the times they flew didn't work. I started with continental for the better schedule, and found out, by accident, what a FF program really offered. I got hooked. When I saw DL offering the same routes, and the same times, with bigger airplanes, and having the status match with CO, I moved over. Now I am back to considering flying JetBlue, since they have their EML seats, and they changed their flight schedule to exactly what I wanted (even though i have to drive 25 mi to their airport, instead of 10 mi to my local one). There are rumors they are addressing the lack of FF program, and if that means priority TSA and boarding access, then they win me back.

FYI, cost is not the top factor in my ticket choices - schedule and FF perks are. I could care less about points or rewards - if I want to fly someplace, I am willing to pay for it. However, I will always buy the cheapest ticket for the routes I travel - I do not consider it prudent otherwise. The exception is when there is a reasonable priced upgrade offered, such as the $30 EML that JetBlue offers. I can justify that on my expense reports, but I cannot justify a FC ticket.