Before I answer your question, I am on record as saying we need to give CGC several years to get his players in the system.
Now to answer, it's because words matter. If you are always painting everything as extreme, eventually, it gets old. Sooner or later, people expect results, and when you have a history of painting everything as overly grandiose, the trust factor goes down. I mean, Billy Mays got famous for this, but everyone knew the stuff he was selling was cheap junk packaged with a pretty bow.
Now, this is not to lump CGC in this boat yet, but the over the top persona and constant use of extremes reminds a lot of people more of an advertising executive and not a college football coach.