While its true that any union organizing on Delta faces the hurdles you listed, the unions own history is yet another hurdle, and its clear that the ibt has a much higher bar to clear than the others. Additionally, I see Delta management is taking a shot at the IAM. It appears the IAM had a similar incident to the teamsters at American. Apparently there were allegations of authorization card forgeries at Delta during the IAM's attempt to organize the FA's - Like the ibt they abandoned their filing when the forgery allegations started piling up ... just another hurdle.
A fair question. One might also ask why isn't the TWU part of this Delta organizing coalition? When was the last time the TWU tried to organize the Delta MX?