Not worth getting your knickers in a twist about, IMHO. It is merely another form of communication - body language that says "I'm ready when you are...". It annoyed me for a few years, then I just accepted it and got on with enjoying the job.. though occasionally I would leave the call as late as possible just to irritate - but always with a smile! On the previous generation of airliner one could call for a heading adjustment to get that hand up onto the glareshield - now we do it all in NAV and the opportunities for fun have reduced...