I think some would argue that quota approaches aren't quite this, but rather that they're a thumb on the other end of the scale. The first thumb is still there because non-compliant cultures that aren't fundamentally converted to becoming compliant at the cultural level will generally continue to be non-compliant cultures and only comply insofar as the quotas require (to take a rather contrived example, you can hire 50% women, but what about when 30% of them are harassed, feel unwelcome, and leave?).
I'm personally of the mind that the only way to really take the first thumb off the scales is to persuade the non-compliant culture that complying is in their best interest. Which seems to be the gist of these guidelines: "We all agree contributors are a good thing. Let's be welcoming to all demographics so we optimize the number of contributors."