We won't hold our breath waiting for consensus, will we?
but nature often 'solves' problems several different ways, and makes irrational choices between alternatives, at least viewed from the standpoint of function.
We should not expect any rational choices from random chance even when "guided" by laws or principles. Although by "irrational" you meant "irrational to us," even that judgment is difficult to make with such a paltry evolutionary contrivance that yields a nearly endless variety of phylogenetic trees.
Well, I do believe in an objective rationality. Irrational isn't irrational to us; it's irrational, period.