It's interesting how that theory has filtered into public consciousness. My sense is that the public doesn't grasp it as one theory among many possibilities, but as a law of nature (a pattern I see for many ideas - people lack perspective that the theory is one of many possibilities, and different concepts were popular before and others will be popular later). You can read people using agency theory, thought not by that name, on HN regularly.
Consider how amazing that is: An academic comes up with a theory, and eventually tens of millions (or more) are repeating it. Is it marketed? Even if it is, many or most of the people repeating it probably have no idea of the marketing. Is it part of an intentional political propaganda campaign? I know other popular ideas successfully pushed on the public this way (one I know of in particular is the "death tax", and I've observed others where the talking points frame and effectively end the discussion).
What incredible power. Is it random? Can it be directed and controlled? Who knows how and who is doing it? I know political groups do it to an extent, as I said, but I don't know their range or accuracy, so to speak.