I'm sticking with my personal opinion in that he just got cold feet, asked to be released, staff said no, and it escalated from there (no sources, just gut feeling).
I agree with your theory on how things turned out w/ Vanderdoes. He has a lot of the consistencies with guys who simply cannot make up their mind and end up skipping around to several different places. These guys usually also end up failing to stay anywhere, and ironically enough, regardless of their talent, their mental game isn't stable enough to ever fully harness it.
Anyway, as for your other point about whose fault it's. I totally
disagree here.
When a coaching staff goes out and sets its priorities on who to recruit, it's their job before they invest a lot of recruiting time into an individual to assess the players mentally (their desire to be here, their history of stability, etc.) This is a VERY important part of scouting in all major sports. If the coaching staff sees any red flags, they need to move on immediately and find somebody who is a better fit.
Brian Kelly and his staff have failed miserably in this regard. They are always wasting tons of recruiting time/resources going after guys who simply don't want to be here.
The turnover rate in recent years has been alarming.
This reflects direct on Brian Kelly. It's a critical issue right now in regards to his recruiting. And he squarely deserves the blame.
1 or 2 big time guys is fine (ok the player pulled a quick one) ... but it's several VERY key guys (the faces of the class) seemingly every class.