You don't actually know that, that's exactly the point. And the pitch is what it should be: "help us win games and you'll play. You're coming here as a business decision, which is fine. But that goes both ways, so you should expect us to make business decisions as well." Besides, if the OC is that bad, why would any decent transfer want to play here in the first place?
The flip side of your argument is that if ND keeps brining in mercenaries, then what reason does a high school kid have to seriously consider it? Why would/should Carr or Knight actually stick with their commitment? They're just going to go out and recruit over you with some 23-yeard old who isn't quite good enough for the League but wants better NIL opportunities, so why bother? Go somewhere else where you'll actually get a shot to play.