Y'all are getting hung up on the correspondence of "words" with "word characters", but you're ignoring the fact that most of the time people want to do awk's version of splitting, matching \S+ words rather than \w+ words (*neither* of which actually matches what people usually mean by words, in any case).
So I think .match should default to .match(rx:g/\S+/), if it defaults to anything. But I still think people would find .words much clearer when reading someone else's code. And the :g would be implicit, so .words(/\w+/) would be still be a shortcut for .match(rx:g/\w+/). Larry