When I was a kid, I had a Justice League picture book called "The Lunar Invaders". I think it was supposed to come with a cassette tape, but I didn't have that; I got the book second-hand.
Anyway, in that book, Wonder Woman was the leader of the Justice League, so to me, Wonder Woman should always be the leader of the Justice League. Also her deferment and eventual acceptance of the leadership role in the Justice League live action movie struck me as the pretty good outline of an underdeveloped plot, so... that just makes me think she should be leader even more.
And sure, that's basically arbitrary, but I don't think it's any worse of a concept for that.