Badger, in order to get the arrow to travel perfectly straight past the arrow rest (no porpoising up or down) you don't need to tiller the bow supporting it at the arrow rest, while pulling the string from where the arrow nock will be. In fact, that would ensure that it DIDN'T fly as well as it could have, had you tillered it while mimicking your own holds on both the bow and string.
If we do mimic our shooting idioms while balancing relative limb strength, we won't ever have to move the nock point to make up for limb strength imbalance. I set my nock point where I decided it would be before I even started the bow, and arrows fly perfect from shot #1.
You're right, bows don't have to be tillered perfectly to shoot 'ok', and sometimes folks have to adjust nock height to adjust limb balance, and they can make ammends. But the farther we stray from optimum, the harder bows are to tune, and the more harsh they are to the shooter and arrow flight. Conversely, the closer they are to optimum, the more inherently tuned they are, the softer they shoot, the quieter they are, the better the tiller holds, etc. You know, all the good qualities bowyers claim to strive for