Yeah, exactly. I would also say Few/Zags is not going anywhere. Wright/Nova has probably achieved that status, as well as Williams/UNCHeat. Self at KU is interesting - he's rumored by multiple fan bases to be a phlandering scumbag, he has the NCAA on him, but KU fans love him. I guess he's achieved this hallowed status. The coaches for life are very few and far between. In spite of national success, I don't doubt that UK fans would get rid of Cal if he went through four bad years. I know he's signed a "coach for life" contract, but I have to believe that the contract has loopholes. I'm also not sure if that contract would have been offered and agreed up on if Cal were younger. UK fans are the most demanding in sports imo. Marshall at WSU has had great success, but I'm still not certain that he's achieved coach-for-life status. I love Bennett/UVa, but if he suffered a handful of consecutive bad years, I bet fans would start getting uneasy.
Coaches are paid quite well, and they must continue to perform over a long period of time to retain their jobs. Look at Gary Williams - he bled Terps, won a chip, and then "retired" suddenly when it was known people were unhappy about his lack of recent success. While not official, there's no way he willingly just agreed to hang it up.