I think this a reasonable take.
None of us really follow OL coaches across the nation deeply enough to assume who could be a great OL coach here with NU as a destination job.
Maybe if the money is right? Maybe if someone wants to get out from the SEC?
But looking back, hiring an OL coach could be because they are on the hot seat somewhere else, lost their job, it's their first job, did a decent job at a smaller school, have Nebraska ties, or are a hanging carrot for recruiting nephews/family members? I don't know.... I don't know who this great OL coach is that is out there waiting to flip their gig for Nebraska.
Since the early 2000's these are our OL coaches. From current to way back.
Raiola
Greg Austin
Cavanaugh (the worst IMHO)
Barney Cotton
Dennis Wagner
Cotton
We all want a priority for an OLINE coach for 2 decades. But we've had so many new coaches and different AD's, it just hasn't worked out that way. :hmmph