Players don't leave basketball programs unless they are unhappy with their situation, relative to their expectations.
Was Anthony Gaines a pro prospect? No. He decided to go to grad school at Siena, closer to home. On paper, thats not a smart decision.
Barret Benson was intelligent enough to graduate NU in 3 years. Instead of sticking around, he left to go to grad school at SIU, where he could get more playing time. On paper thats a bad move.
Ryan Young finished his degree and sought better opportunities. He found one at Duke. Having been shortchanged by his coach, he felt no desire to stick around. Smart move.
Pete Nance tested the NBA waters and learned that playing out of position is not good for one's draft prospects. He went to a far better situation at North Carolina, where he could make up for lost time (developmentally).
Rapolas Ivanauskas was the prototype for Pete Nance. Stretch 4-5. A lanky 6'10", pretty good shooter. Collins redshirted him, then he got hurt, got buried on the bench. His father decided that Collins had no idea what he was doing. Son left NU to become Patriot League player of the year the following season. He's in his 3rd year of European play.
Casey Simmons arrived in Evanston with a lot of fanfare. After a single year in which his playing time diminished, he left to go to Yale. Who knows what promises were made when he was recruited? Who knows what the coaches told him during the summer to convince him to pursue that Yale diploma...
Miller Kopp was supposed to be a team leader. He played heavy minutes for 3 years and then abruptly transferred to a school with less academic prestige. An odd move... and he criticized Collins on his way out the door.
The story on Doug Collins was that he took credit for wins and blamed the players for losses.
And his teams turned on him.
The story on Chris Collins a couple years ago was that "the word is out that he's in over his head."
If both Matt Nicholson and Luke Hunger stay out of the transfer portal after this season, I'll be surprised.