I pretty much always use Gday when transferring aircraft to the next frequencies. Guess its become a habit after 20 plus years and take no offence if it is not reciprocated.
I'm not big on Merry Xmas when I'm sitting at work on Chrissy Day, I try to stick to just Gday so I'm not reminded of what I'm missing (again). Its like a plague, one pilot throws it in and then everyone else feels dutybound to do it so they don't sound like a miserable bastard. It dies out for a half hour or so and then someone else pipes in with it, and off we go again.
I listen to a fair bit of talkback radio on the ABC, and admire the hosts who are asked by nearly every caller " How are you" and never reply "Well nothing much has happened in the last 45 seconds since the last caller asked so I'm still good, now will you get on with it". Lots of self control on the ABC.