Well, if you read the highlighted part, you'll see that the MEC advocated supporting the NPRM (i.e. internal FAA) process for chance. That's not what happened. Instead, we got Congressional change. So much for sucessfully "getting on the train."

The "and for the protection of our members' seniority rights" quote is a "motherhood & apple pie" synonym for retroactivity. By couching it in such terms they hoped that it would escape our attention that Webb (with the MEC's blessing) was planning to ignore the desires of the majority of his constituency. It wasn't necessary. Congress wasn't planning for it, nor was the FAA, and it's only through Webb's initiatives that we saw the wholesale migration of NDs back to the front.

It's one thing to accept an inevitable rape... it's quite another to subsequently invite additional participants. Your highlighted quote doesn't support Webb's action, it indicts the entire MEC. Hence the "no incumbents" sentiment among a majority of the crewforce.