Kevin O’Neill (1994-1997)
Kevin O'Neill was hired by Tennessee in 1994 after a successful run at Marquette, going 86-62 in five seasons and reaching the Sweet 16 in 1993. However, O'Neill's success did not translate in Knoxville, nor did it translate anywhere else after he was fired from Tennessee.
O’Neill survived three seasons in Knoxville, all losing seasons and never making it beyond the first round of the NIT.
He also had a rough time at Northwestern, Arizona, and USC before trying his hand at the NBA. I did a little bit of research on O'Neill since I was not born when he was in Tennessee Orange, and things were not good.
During his time on Rocky Top, he was known for verbally attacking his players and giving them unsavory nicknames that would be spread throughout campus. He treated his players poorly across the board throughout his time in Knoxville and college basketball.
One example listed in this Northwestern basketball article highlights O'Neill reacting to backup Jason Moore, who made mistakes on the court, resulting in Tennessee losing its first-half lead. O'Neill responded to this by saying, "You better hope you DIE before halftime!" I'm sure there are many more examples from his time at Tennessee, which is probably why he was "never successful on Rocky Top or anywhere else.
He's nearly unanimously disliked as a coach and person. He almost destroyed the Arizona basketball program with an official 0-14 record as head coach after his 19 wins were vacated. He also had single-digit wins in his final years at Northwestern and USC. None of this directly applies to Tennessee basketball, but it shows the type of coach that Tennessee decided to hire in 1994.