[...]
Is there a reasonable way to refute this logic: If the ghost never makes a mistake, it has a 1.000 TPA all the time. [...]
Nobody is refuting that. It's just that a hypothetical "rating" for a pretend player who never misses is not, unless somebody can convince me otherwise, a particularly useful or interesting thing.
Here is something different that I DO find interesting. Suppose I'm a 530 and I play for a few hours in my basement every Tuesday and Thursday.
On Tuesday, I always play 8-Ball games against my friend Harry, also a 530. After many Tuesdays we're dead even, 150 to 150, consistent with us both playing at the same speed, likely around 530.
Harry works Thursdays, so I play by myself. I always do the same thing. I break, remove all the stripes, take ball in hand, and try to run out the solids and 8-Ball. After many Thursdays, I'm at 150 successes and 150 failures. I have the same success rate at this task as I have playing games against Harry.
Moving forward, a GOOD Tuesday outcome is one where I beat Harry--win more games than I lose.
and a GOOD Thursday outcome is one where I win more than I lose against Victor, the name I've given to the opponent of success on the Thursday task.
So Victor is already interesting to ME. He acts like a worthy opponent. If I'm distracted I'll probably lose to Victor. If I don't stay down on the shots, I'll probably lose to Victor. If I can bring my A game, I'll probably beat Victor.
What would make it even more interesting is whether Victor generalizes as playing the role of a 530 opponent. For instance, a 630-rated friend would win about 200 to 100 against Harry. And a 430-rated friend would win about 100 to 200 against Harry. Would these players fare similarly playing "games" against Victor? If so, the idea of assigning a rating to a task is, imo, even more interesting and useful.
The preliminary evidence is it does work out. That suggests "9-ball ghost on an average 9-foot table" has a rating, and "9-Ball ghost on a Valley bar table" has a different rating, etc. These are all defined with a task and the human player attempting the task first.