Let's not and say we did

In today’s edition of his weekly (free) newsletter, World Wide Words (subscribe here), Michael Quinion puts his foot down on the alternate/alternative debate:

ALTERNATE Several readers queried my phrase "Harry Turtledove's
alternate history.” No, they cried, it should be "alternative."
"Alternate history," for an SF story which takes place in a world
in which history has taken a different course, is first recorded in
1957 and is older than the other form by 20 years. It was coined in
the U.S., in which "alternate" has taken over much of the territory
of "alternative" during the past 50 years. It is mostly the British
who prefer "alternative history," though even here -- as you will
note from my using it -- the other form is often used because of US
influence. Let us not, please not, argue the relative merits of the
two words.