Well I think Mckenna's talking about ALL culture, not just the culture we don't like, or at least all culture not based on boundary-dissolving plant hallucinogens. (Which, if you haven't really been there, I imagine is hard to agree with, but I think it rings true.) In fact I think he's specifically talking about the culture we do like hence the wording 'culture is not your friend' - you think it is, but it is not.
Towards the end of the video when someone in the audience asks: "How do we fight back?" He answers: "By making art." So you're telling me that's a euphemism for getting high on 'shrooms? Are you nuts?
Any endeavor or activity that is part of the bond building communication system between humans, hell, every aspect of our beings can and will be exploited by those who seek power. All culture is not our friend? As a generalization that is a particularly useless statement. Culture mediates and enriches communication, incorporating all forms (even non-verbal thought forms), strengthening social bonds, which are, in turn, necessary to survival. Any resistance movement must understand the weapons aimed at it, for defense or counter attack, including how our need for culture is exploited. Don't eschew, disdain, or dismiss it, understand it and use it.
As for 'shrooms, I guarantee you the thugs on top have done all of those drugs and know how to exploit those states of mind as well.
My dear departed friend happened to think that art was such a powerful tool for change she instituted a new grant program that rewards artists for using it in novel, dominant-culture jamming ways. Well, we'll see how that works out.