I used to think that, however I would like to point out that Keynes did believe that the gold standard was necessary. What we have in economics now are Neo-Keynesians, who perhaps can be said to have hijacked Keynes.
Keynes advocating against the reintroduction of the gold standard, and then—when Churchill got it reintroduced anyway—for its abandonment until it was again abandoned.
You must have mistaken Keynes for someone else.