It's being unfair to Holgorsen to call that a "mistake".
A coach's primary job is to win games. Everything else is secondary. I wouldn't want a coach who communicates constantly to us, because at some point that takes away from the time spent on what really matters.
You can certainly state a personal preference for a more verbose coach, just remember it has minimal importance in the big picture. Whether it's the folksy and open Bobby Bowden or the dour and secretive Bill Belichick, all types of people and leadership styles can and do succeed. Dabo is a Bowden, Dana is someone else entirely. It's not fair to criticize him for his inherent personality.
In the specific case of Holgorsen, ask yourself this: Is his time better spent explaining to us how he PLANS to take the program to another level, or working behind the scenes to actually achieve it?
Some of us are already unhappy with Holgorsen's performance to date. A coach in that position doesn't also need to be wasting time on communicating a bunch of grandiose ideas for the future, because if he can't begin winning more games in the present he won't have a future.
No, I'd say Holgorsen's focus is probably right where it needs to be. Whether he can deliver results on that is another matter.