Gotta push back on this quote and your other quote that "no one saw this coming." Perhaps no one saw exactly this result. Gattis' resume was there with the big award everyone referenced. On the outside, it looked like we grabbed "a playoff OC who'd just won the Broyles." It was the consistent argument in support.
There were tons of people - here and on twitter arguing with Gattis himself, lol - who were wondering/hoping/praying his previous approach was really just a product of "being limited by a crap QB." But, the offseason was full of concern and skepticism about what we'd look like and how TVD would look vs how he looked during his 300-yard run last season.
Personally, it was my #1 question in August:
https://www.canesinsight.com/threads/my-biggest-questions-going-into-fall-camp.178845/
But, I can link/screenshot some even earlier comments/questions about how it'd look and how it better be something more/different than what we'd seen at UMich. Here's one:
I'm definitely not the only one. FAR from it. I was skeptical, cautious, and willing to wait and see if he'd come in with something more aligned to TVD's strengths and weaknesses (they're still there, maybe worse). He did not. I think part of TVD's yips are precisely because of what he's being asked to do within the scheme and playcalling. That's a rough start to your coordinator function.
There were others who had even stronger stances - saying he'd outright suck. I presume based on what he had shown and they figured it'd be the same here. I didn't go that far because there's always a chance someone adjusts. Instead, SO FAR, he's only validated concerns. If he changes now - and he already went to hurry up more last game - it feels more like an admission of guilt than the genuine understanding of what we needed most.