Why does your turntable sound the way it does.

Ok, we all seem to agree that turntables sound different, and there are any number of upgrades to a basic turntable that are offered, up to and over $100k. But what is it that causes a turntable to sound the way it does. After all, isnt the basic principal that the table causes the groove undulations to pass by the stylus at a certain speed, thereby creating the sound we hear. If that's true, then only something that affects that point of interaction should have an effect on sound. Forget of course, differences in cartridge, tonearm, wire or preamp. Just think of the turntable itself.
Now, we hear that idler drives are more impactful than belt drives, belt drives are quieter and release more inner detail, direct drives maintain speed and tempo better, aluminum platters sound different than acrylic or glass or MDF. Platter mats can change the sound considerably. different bearing materials and precision in manufacture can change the sound. but why?
Is there a basic sound to be acheived when everything is perfect, and what we are hearing is actually a distortion of that sound based on resonance or time or torque or vibration or whatever. Is there a means of measuring what a cartridge can do in a perfectly set up system where there is no influence on the stylus/vinyl interface and the cartridge is free to follow the groove undulations without exterior influence. Is this perfect environment found in the cutting head, or is it also subject to the same influences as the playback stylus. And if so, how can we ever account for that effect in our playback systems.

So, fellow Audiogoners, what do you think has the greatest effect on vinyl playback as far as only the turntable itself, and what do you think can be done to ammeliorate those effects.