I think he's saying you are better off being a bigger fish in a small pond than being a very small fish in a big pond only to lose your growth and position in a merger. In many ways he does have a point.
The counter argument is that even though a merger cost me my wide body gig and schedule, I make more than if I had gone to work at Jet Blue. Using an apples to apples comparison, $122K v/s $94K.
Where it gets interesting is if I were willing to bid bottom of a type that Delta has outsourced to regional carriers, in that case I'd be making about $130K at Jet Blue. At Delta I am so far from upgrade it is not even a consideration.