If you use metrics such tourney appearances, wins/losses, and recruiting you would agree that the programs were upgraded. If you think Bruce Pearl did a better job at Tennessee than C Martin than I really can't reason with you.
But none of this matters that much, I know he will do very well at Illinois. I played bb in Chicago's SE and know the scene. C Martin played BB during my high school years, he carries a great reputation throughout the state in the neighborhood of Dee, Frank Williams, Sergio, Deon, Gill, N Anderson, etc.... He is one of the few who won state championships, had college success, played in the NBA, and has had coaching success. C Martin's connections go back to our Flying Illini, trust me he is well respected among our greatest alumni from the Flying Illini through the great Peoria teams even though he played at Purdue.
This isn't info you find at Wiki or google. No connection to any players but I have talked and shot bb with many former Illini (not going to name drop). Most of them were at UI when I went there and are from my generation. You name C Martin as the coach and I predict that the big names of Illinois and IHSA bb are going to rally around him (Bardo, Deon, Frank, Gill, N Anderson). Imagine going into Peoria, Chicago, and STL metro gyms and the coaches really want to send you their players. Still some coaches and street agents will want their agenda, but on the above board recruits we will win more than our fair share. If you look at the wins/losses at SW Missouri, Tenn, and Cal I think you are missing the bigger picture.