That letter is the very heart of the displeasure DAL pilots had/have for the CMR pilot group. I'm guessing that previous DAL management also didn't care for CMR pilots because of the strike. Even today CMR pilots carry the stigma of JC's fu. I laugh when jumpseaters and current DAL FO's aren't upfront with their CMR roots. It isn't the first thing they mention.
As for me, I really don't care about JC. But... CMR guys have been the only guys in the industry to treat me badly on an offline commute. Not a jumpseat, but the $20 pass ride we had to buy in '93. So I hate because of that.