If we're being honest, let's admit that some of these guys are hired guns, mercenaries if you will (and if we're being really honest, we don't care if they get their degree as long as they win games. Ivey is going pro this year. He's played 2 years for Purdue. He may or may not ever graduate with a Purdue degree, but he'll help Purdue basketball win a lot of games which is what we all really care about.)
This is what the portal is for: find a guy who can come make an immediate 1, maybe 2 years impact and that player is potentially the one to get you over the hump.
Again, you're assuming a guy from the portal would be a bad teammate.
Was Wheeler a bad teammate or just in the wrong situation? But then again, Wheeler's not a future pro, Carr is.