^^^ I see what you're saying, and I completely agree that what's accepted/expected varies from region to region. (BTW, I don't know if you were thinking about me when you speculated about jeans and tee shirts "in the west," but I'm in North Carolina.)
As for a comfort difference between jeans and chinos, there's a
definite comfort difference in the summer.
And on that note, FantASTic, when we go camping between June and September, we wear chinos (or shorts) as well. Otherwise, everyone is in jeans.
Oh well, it's late and I need to go take my jeans off and get ready for bed.