@IRyan
Good point.
The “trick” in the question is “Well, Bhodisattvas don’t have attachments, therefore don’t have desires, therefore don’t act.”
But, as you correctly insist, consciousness—and therefore life—requires that humans regularly choose among competing alternatives, and therefore bhodisattvas do have desires in this sense, and do act.
Did a bit more reading, and according to this article, Nirvana is the cessation of Dukkha. While on its face, this would seem paradoxical (hence my confusion), it may be that there is a more subtle interpretation I have yet to grasp, something more akin to the Taoist Wu Wei, rather than Mises’ description of the “Vegetative Man”. Now, whether or not I can understand this nuance, or whether this “nuance” is nothing but morally charged semantic Three-card Monte, is something to meditate on ; ).