While i dont really care so much about the mail client in itself, I would gladly use something else besides outlook, if it would integrate itself into the exchange protocol so well.
It feels like E-Mail is a solved problem, but its really not we all have just more or less agreed that its good enough. I Remember when i started using ot years ago (i even have private exchange since more than 10 years), i thought -this - this is how email is going to become everywhere. But it never really cought on, except of course if you now also book office 365.
Comming back to the main topic though: i dont think that extended hubris and sarcasm is a sign of a healthy project, but more that of a hurt child. If your fixes would have been according to the guidlines of mozilla to begin with, im sure your patches would have been merged.