In Gatsby in the valley of ashes, why is it only "with a transcendent effort" the ashes take the form of men?

The ashes naturally form houses and rising chimneys because ashes cling to those objects and are produced by the chimneys. However, those are dead things. The ashes also rise and take on life--a paradox, since ashes are dead--and so they have to go beyond (transcend) their own nature and assume life itself. The word "transcendent" is ironic, humorous, and poetic all at once, a characteristic Fitzgerald touch.