JetBlue is not a secondary carrier. Nor is Spirit or Frontier. The only secondary carrier is Copa, which flies from Panama.
The heck are you talking about? COPA is not even a US based airline.
The most influential airlines in the US are the legacy carriers (Delta, United, American/US). Then you have your secondary/regional/low cost carriers (Southwest, Virgin America, JetBlue, Alaska, Hawaiian). Finally, you have the ultra low cost carriers (Frontier, Spirit, Allegiant).
If the poll is asking for opinions on which airlines are better, and mixing the legacy carriers with the secondary carriers, I believe the omission of VX (the most direct competitor to B6), AS and HA (both of which are mighty in their own spheres of influence) does not allow for proper comparison between the aformentioned carriers.