I don't mean to diminish the larger point you're making about feminism not having middle ground, but from an interface design perspective, a dial very much implies a continuum of settings. When there isn't middle ground, the interface should be a toggle switch instead.

Of course this is art, not a real device, so obviously a dial is appropriate because it's a response to being told to "dial down," not "switch off."

(I almost feel like there could've been something different about the way the dial was depicted -- maybe with a range with "raging feminist" next to "complicit" and something more extreme above it, or maybe indeed using a toggle instead of a dial -- in order to emphasize that "raging feminist" already is as "dialed down" as you could reasonably ask for, but such UI realism would probably just clutter up the design without improving the message. As art, I think the artist got it right as-is.)