All this really says is that there were background players and deep background players.
The holy trinity is Spock, Kirk, and McCoy. We love them all, but the show is this triad. We've seen plenty of other people at the helm and the comms station.
I agree. But if the TOS movies had just Kirk, Spock, and McCoy -- with some Scotty thrown in, fans would have noticed the glaring omissions of Uhura, Sulu, and Chekov (and Chapel).
In fact, the minor roles in TMP for Uhura, Sulu, and especially Chekov was a major point of contention regarding that film for many fans.
Sure -- Kirk, Spock, and McCoy are the triad, with Scotty thrown in just below them. But fans even as far back as TMP expected Uhura, Sulu, and Chekov, too. Those fans STILL expected those characters for the new films, so that's who they got. Like I said, leaving Chekov out of ST09 just because he would be too young would have caused a fan uproar.