T.M.
Again incorrect. Frtr guys who joined on the frtr scale (again a lesser scale than B scale) knew before they joined (or as they joined) that there was the possibility to go for an early command on frtr salary. Hence, the reason many of them actually joined. i.e. planning to attempt the command course on the frtr. This also allowed them to hold their base (quite an important item after the raise of retirement age to 65). Plus, again, it isn't necessarily left seat envy as you call it but surely pay packet envy as (again to hopefully help you understand) the pay is more than pax FO. Please do the math dude.
And if you joined on B scale but didn't actually know it was a "scale" lesser than A scale, then I would suggest you should have done more homework.
Point is, guys join a company because it is better than where they were working before. And there was no longer an IFALPA hiring ban after 2003 or 2004 to say "hey wait a minute maybe I shouldn't accept this lower pay scale". It was the only way to join as a DEFO, as it currently is today with the UFO pay scale.
PS: are you ever going to explain why you started this discussion on this thread? guess not.