Raul- Not to be a nit-picker, but it seems to me that your accuracy analogy to the earth;s rotation is counter to your arguement. Unless I am mistaken, the earth's rotation is not "accurate" if by that you w/o variation. For example earth wobble a bit on it's axis and it's rotation is gradually slowing due to predictable tidal effects and unpredictable or stochastic effects, such as massive earthquakes. As Wikipedia notes"
The Earth's rotation axis moves with respect to the fixed stars (inertial space); the components of this motion are precession and nutation. The Earth's rotation axis also moves with respect to the Earth's crust; this is called polar motion.
Precession is a rotation of the Earth's rotation axis, caused primarily by external torques from the gravity of the Sun, Moon and other bodies. The polar motion is primarily due to free core nutation and the Chandler wobble.
Over millions of years, the rotation is significantly slowed by gravitational interactions with the Moon; both rotational energy and angular momentum are being slowly transferred to the Moon: see tidal acceleration. However some large scale events, such as the 2004 Indian Ocean earthquake, have caused the rotation to speed up by around 3 microseconds by affecting the Earth's moment of inertia.[21] Post-glacial rebound, ongoing since the last Ice age, is also changing the distribution of the Earth's mass thus affecting the moment of inertia of the Earth and, by the conservation of angular momentum, the Earth's rotation period.
Beethoven is different from Bach. Was Heifetz better than Perelman? Which conductor led the best performance of [insert symphony of your choice here]. Was Pavarotti "better" than Caruso. Are we talking about precision or accuracy? Obviously, these are rhetorical questions. Obviously there are some basic accuracy parameters that must be met, esp for a mechanical system like a TT/tonearm/cart.
My purpose is not to argue about your specific analogy but to point out that the use of objective criteria to define what is essentially a subjective experience may, ultimately, be futile. Reproduced music is not the same as the original performance. Never was and never will be.