It's like "preventative", which, for many decades was simply "preventive", which is, in itself, correct, and therefore preferable. Some, no doubt, defense contractor employee here in the U.S. thought it sounded good and wrote it into something, and, well, now it's in the dictionary, and will never go away.

I remember seeing a banner that said, "An ounce of preventation is worth a pound of curativeness," spoofing the saying, "An ounce of prevention is worth a pound of cure." This says it all, as I knew at the time that the fellow who made up the banner agreed with me, that the defense industry tends, as much as anyone, to emphasize appearance over substance, hence would readily invent words in that manner just to make things more pretentious.

Nevertheless, I'd like to see it in print, having been produced in a country where English is the principal language and published by an organization at least minimally concerned with correct syntax, grammar, and orthography.

RE