In the original context, the alleged desirable ambiguity was the ability to concisely omit information--that is, to say "people" instead of "men and women". Tabooing 'ambiguity', I'd frame this as a matter of having words for large sets rather than requiring speakers to construct them out of smaller sets, and say that this is a good thing if those sets are commonly referred to.

On a similar note, there can be intensions whose extensions are not agreed upon--"good" and "right" spring to mind. At first I thought it would be necessary to have words for these, but upon reflection I'm not sure. Could we replace them with more specific words like "right according to classical utilitarianism" or "right according the ethics of the person this word relates to"?