First of all, look who all 3 coaches were replacing. Doc Sadler literally was probably the best of the bunch. That should tell you why all 3 coaching hires were not immediately hated by the majority of the fan base.
Miles... He does a lot of good things off the court, and didn't sound drunk constantly like Sadler, and on the court caught lightning in a bottle 1 year. His ability to recruit save his skins for a few years, but the losing has caught up. He probably should have been canned at the end of last year, but he has to win this year or will be gone. He was definitely the best of the Osborne hires in my mind, and unless he turns it around this year, will still be a failure of a hire.
Now, as for Erstad... He replaced Mike Anderson. Mike Anderson literally destroyed the baseball program (and Tom kept him too long), so Erstad, while something different from the that tool, is still a guy who walked in here without ANY head coaching experience. You may not know them, but I know people who questioned that move right from the start. But TC, so we'll give him a chance, can't be as bad as Anderson is what I heard over and over. Few years later we have exactly 1 regular season championship & a bunch of early exits in tournaments. Wonderful. Oh and he isn't going anywhere because he donates a bunch of $$$ to the school, so now it feels like the program is hijacked, which is even better.
Pelini... Christ sake don't give me the record BS again. 408 lost every chance he had to win a championship, and got a 70 spot put him vs. a 4 loss wisky team. Came close vs Texas, but his inability to put together even an average offense killed the greatest defense I'll probably ever see. His recruiting was average at best, his development of his highly rated players was piss poor, and he hated the fans. Yeah, 9 wins a years was nice. Congrats. They meant nothing in the long run. How TC can defend this numbskull even today just baffles me.