Every place I've ever worked, I've noticed a strong correlation between unproductive workers & their low compensation.
You are looking at this the wrong way around.
for sure, if you are on a low salary you will be less keen to work hard and therefore be less productive.
But once you hit the reasonable salary mark, say 60K, you will be motivated much more to keep your job so the work rate will improve. Any extra salary increase from here on will be looked at as a bonus but will not make you work even harder.
It's easier to illustrate the opposite. Cut someone's pay, then watch their attitude & productivity fall.
That may be true, but you are using some kind of inverted logic here in order to campaign against the 100K system.
In my experience, giving someone a raise does not lead to greater productivity.
Now you are being caught up in your own logic inversion.
But if a raise is warranted, then not giving it to them will lead the to find another job with higher pay.
Of course, you are assuming that the worker can just do this by choice.
However, for most people, this is not the case. You have to accept your salary whether you like it or not.