I guess there are two extremes from which you can view this news:
In the harshest light, we simply don't have the resources Kentucky does. Never have, never will. Whatever concessions were made to keep Scott Drew in Waco likely tapped out the donor base's ability to stretch to retain Brooks at a level that would even approximate the stack of cash UK threw at him.
Hopefully he left on good terms, but the apparent glee about going to Lexington, combined with his less-than-stellar body language on the sidelines and in timeout huddles this past season makes me think he might be happy to be gone. If that's the case, I doubt we'll ever hear anything negative out of Drew about it, however.
In the most generous to Baylor view, Coach Drew has always had a few designated roles on his coaching staff, at least after the first few years when everyone was a recruiting junkie:
1) HC-in-waiting type
2) Player development specialist
3) Young, hotshot recruiter
At first, everyone filled the "hotshot recruiter" role (Morefield, Matt Driscoll, Tang, even Coach Drew himself). Eventually, they started to specialize, and it seems like Driscoll was the first HC-in-waiting, and thus, the first guy to get hired elsewhere. McCasland and Mills spent time in both the player development and right-hand man roles during their time here.
Tang started as the hotshot, moved into player development (see his improvement as a defensive coach, and how good KSU has been on defense since he took over), and eventually progressed in his X's and O's chops to be the HC-in-waiting. I think that became the ideal model, and it seems like the one we tried to fit Brooks into.
Not to discredit his actual basketball chops, but it seems like he was a guy who never really progressed beyond the "hotshot recruiter" role, but he was here for 8 years, and was very good at it, so he progressed to a defacto "HC-in-waiting" payscale without actually having the requisite skills for the role.
This might be a mutual decision. Coach Drew saying, "go get paid, get some great outside experience, and stretch yourself," and Brooks acknowledging that he has some growth to do that is better accomplished with a change in scenery. Or, maybe he's more like a Rick Stansbury type, who is really good as a recruiter - good enough to get multiple HC roles over the course of his career - but never a good technician.
If this more generous interpretation is true, we're likely retooling all the roles (see Peterson leaving the program as well, leaving the recruiter, development, and right-hand roles all vacant at once). Bill Armstrong from Link Academy can step in as the hungry young recruiter (at a lower pay scale), maybe Tweety Carter moves into the player development role, and we hire an experienced X's and O's guy to fill the Associate HC role.
This is all my conjecture, and as is the case with most of life, the truth probably lies somewhere in the middle of these extremes.