The trouble with Mayo is the idea of him is much better than the reality.
Young, former player who should be able to connect well with players of today. Had 8 years as a player, including a Super Bowl win, and 5 years as a coach under Belichick, so presumably learned about what it takes to win in this league. Spent some time working in media, so should understand those interactions.
I don't know if it's actually a case of inexperience being a key problem. I think it's personality. I think of Josh McDaniels two head coaching disasters, and how he made it seem after the first failure that he had learned about how he needed to change to make his second chance a success. But then he basically made the exact same mistakes, and it's because it's so difficult to change your personality.
With Mayo, he's incredibly driven. He'd been after this job for years, so his post-playing career has been all about self-promotion. That leads to where we are today, which is someone who's so focused on making himself look good, he'll throw anyone under the bus to deflect blame. And when he receives negative attention for that, he walks back the comments, but that also just makes him look bad. He got the job through questionable means, so he's always going to be concerned about holding onto that power because he didn't get it through true merit.