the argument is valid. His crit has nothing to do with his lore or the rest of his kit. Two, getting frequent non-stop crit with enough AS is actually better than than 50% crit chance at 100 ad. Consistency counts. But, it also depends on how you play as Yasuo, since it does require skill to use him. BUT, it is an ironic thing, since 100% crit takes literally no skill, and rewards you for newbing up. Trust me, i suck with Yasuo, yet i get rewarded every now and then simply because of the passive's constant crit.
You would think things would go worse, but not really. Had he had a different non-crit related passive, i think i would have been wrecked even if said other Yasuo was OP. Crit rewards too much for too little. Even when they literally miss everything else, crit is there to save the day. Trust me, i have made one too many blunders XD.