Much ado about hats.
Proof positive pilots will always find something to complain about.
Smile, wear your hat when it's reasonable to wear your hat, look like a professional. Is there really more to say on the issue? That goes for both sides, too, I think there are bigger fish to fry for CP management right now than a couple of pilots not wearing their hats. Plenty of other codeshare partners for DL and AA don't wear hats, we aren't unique. How about that Delta Guaranteed Interview we were promised, work on that... or RNP .3... or going and getting more flying... or how the hell we're going to staff this airline when attrition goes soaring this winter.