The copy editor, like a testosterone-crazed male cat, likes to mark his territory. His territory is your manuscript. But like a cat, he is lazy and easily bored, which leads to inconsistency. He starts out changing every occurrence of ‘identical with’ to ‘identical to,’ but then tires of this game so that the end result is a mishmash. He would have spared himself the bother had he appreciated the simple fact that in the English language ‘identical with’ and ‘identical to’ are stylistic variants of each other.
My advice to editors: stick to questions of formatting, and to the correction of obvious spelling and grammatical errors. Keep your political correctness to yourself. Don't replace the gender neutral 'his' with the abomination 'his/her.' Keep your stinking leftist politics out of my manuscript. And don’t try to be what the Germans call a Besserwisser: don’t presume to know better what I want to say and how I want to say it. My writing is an exacting labor of love; your editing is a lousy chore you can’t wait to be done with.
Now, having vented my spleen, I look at the other side of the question. Where would the journals, and we who publish in them, be without editors and their grunt work? May they be adequately compensated! May their teaching loads be reduced! May 72 black-eyed virgins greet them at the portals of paradise!