As usual, you continue to hack away at a strawman argument nobody is coming close to arguing. In fact its already been addressed by jalfa above, if I may quote:
The bolded is the strawman you continue to throttle without really addressing what anyone is actually arguing.
This is a graph of the top 30 players in Usage rating plotted in relation to their scoring efficiency from last year. These were the best scorers in the NBA, and while its not exactly linear (there is a bit of tug-of-war between volume and efficiency, where greater volume allows for lesser efficiency, and lesser volume demands greater efficiency). You could actually extend this graph further to the left, where you will start seeing more roleplayers appear on the lower end of the usage scale and higher end of the efficiency scale.
You could probably do the same thing for FG% and eFG%, but those are both flawed measurements so your results are going to be off. eFG% doesn't account for the value of free throws, and FG% accounts for neither the value of free throws nor the relative value of three pointers.
So really, TS% is not "mashing" anything up, its rather distilling out a very specific skill (scoring efficiency). Its not crazy to suggest that a DeAndre Jordan dunk is more efficient than a Cousins hook shot. But in order to get a better picture of the player, you need to account for volume. Jordan isn't going to be able to get up a dunk whenever he wants to. A Cousins hook, however, is far more repeatable.
context is very important here, as it always is. TS% is useful when you compare players fulfilling similar roles, using up similar amounts of possessions within a comparable hierarchy. it gets complicated once people start using it to claim the superiority of player A (a third option/roleplayer kind of guy) compared to player B (a second option, whose team relies on him to create shots for himself and others), or something along similar lines.
This is a graph of the top 30 players in Usage rating plotted in relation to their scoring efficiency from last year. These were the best scorers in the NBA, and while its not exactly linear (there is a bit of tug-of-war between volume and efficiency, where greater volume allows for lesser efficiency, and lesser volume demands greater efficiency). You could actually extend this graph further to the left, where you will start seeing more roleplayers appear on the lower end of the usage scale and higher end of the efficiency scale.
You could probably do the same thing for FG% and eFG%, but those are both flawed measurements so your results are going to be off. eFG% doesn't account for the value of free throws, and FG% accounts for neither the value of free throws nor the relative value of three pointers.
So really, TS% is not "mashing" anything up, its rather distilling out a very specific skill (scoring efficiency). Its not crazy to suggest that a DeAndre Jordan dunk is more efficient than a Cousins hook shot. But in order to get a better picture of the player, you need to account for volume. Jordan isn't going to be able to get up a dunk whenever he wants to. A Cousins hook, however, is far more repeatable.