I think you are truly failing at understanding the magnitude of how desperate our athletic department was in the 90's financially.
I think you are also truly failing at understanding just how unique our athletic department is now. They donate over $5 million annually to academics. They are one of only like 7 or 8 in the entire country that is self-sustaining. Every single sport has had facility upgrades since 2002. If you think anyone could have done all this, that it's not just because of Castiglione, you're living in a fantasy world.
Castiglione is recognized nationally, both by his peers and by the most prestigious publications as one of the top 3, if not the best, A.D. in the country. There's a reason for that.
I don't think Castiglione could get fired for the basketball situation, but I do think it could tarnish his otherwise stellar reputation.
However, I will also add the AD was in good shape (financially) under Duncan and when he left and the job was handed to Steve Owens, which was a big mistake looking back, the AD started going south.
Castiglione did get it back in order, but it's not like he was handed the OSU athletic department. We had a number of big donors waiting for the chance to give money to a winner and he hit a homerun with Stoops and the dominoes started falling.
Boren, IMO, deserves as much credit for the success of the AD as does Castiglione. Boren has been involved in all the big donations, even most of the big athletic donations.
For anyone to think Castiglione is bigger than the university, they are wrong, however, I don't see him being fired for the state of the basketball program. Everybody is allowed a mulligan, and Joe will probably be allowed more than 1, but I expect him to fix the basketball situation and everything will be back to normal.
I do not think he will make a change though until the NCAA is done with the investigation because he probably will be hard pressed to convince a good coach to take this job with possible NCAA penalties looming.