The calendar is a bit of an issue. Shall we celebrate the Nativity on December 25, or January 7? January 7 would merit great deals, but December 25 is the day you get off from work.
Politics. That's what it really is. The priest I know in Miami would use both calendars. He'd say "next week we will be celebrating such-and-such feast. And if you miss that, come back in two weeks when we will be celebrating such-and-such feast Old Calendar!"