The practice is worse than that: Impact players are being recruited off rosters & going through the charade of entering the portal. But, honestly, we live in an era where Coach K is as dirty as any coach in America, so it is what it is.
For many more, these are the same kids who simply would have quit, been encouraged to transfer by their coaches, or simply not had their scholy's renewed (depending on the school). The portal is little more than a false sense of control for these kids & I suspect reality comes quick and is hard.
For the rest, as they say, delayed gratification built the middle class in America, and the need for instant gratification will be it's demise.