To be fair, the initiators of the "Open Source" movement also co-opted a term that previously had a much more flexible meaning (and had been around for more than a decade at that point.) Just writing a document attributing specific criteria to a term does not grant one authority over the use of that term.

Ironically, the roots of the Open Source movement are a direct reponse to the Free Software movement largely because it was considered too ideological and unfriendly to corporate interests (i.e. monetization.)