I think the problem is that what folks think are easy adjustments to make in game really aren't. For example if Cam is getting pummeled on 5 step drops going to screen passes isn't going to magically change anything. And going to quick timing passes sounds good if you are running a WCO but are not what a Coryell vertical system is built on. If it is a simple adjustment you can pretty much figure the coach who develops a good pregame plan would also actually have planned certain adjustments if the defense changes up based on the likelihood that they have seen other teams make similar adjustments. This is a copy cat league.
The issue is actually more complex and is usually more about constant adjustments from play to play, teams disguising what they do, and players winning individual matchups as they progress through the game. A DE setting up one move for 3 plays by doing something else and then on 3rd down go to that move. Playcalling gets too much credit or blame while execution and physical talent are actually much more important and are often overlooked or minimized.
The offensive coached have been working since the end of last season to revamp this offense. They worked to learn about other systems they could apply and that along with the new toys (and an upgraded Oline) think we will be please with the results. There is also a new consultant in the mix. Willingness to learn and change are very good traits in an NFL coach. I too think the Shula bashing should stop. Let's wait and see the results.