I think the article is very good. Petzing needs to have the offense let players do what they do well.
In his defense, I think being an OC with Murray as your QB is a tough challenge(not a knock on KM for all the fanboys). He's not your typical dropback QB in a structured offense. He and Bryce Young are similar in that regard. People say Kyler's size isn't that much of an issue and use Drew Brees as a comparison. Difference is, Brees was the quintessential pocket QB. Murray is far from that, struggles from the pocket and looks at the rush rather than downfield after about 2-3 counts. If Murray could dropback, hit his spot and throw on timing/rhythm, the offense would run much differently. That's just not his game.
You have to design an offense around Kyler's skillset and Petzing has struggled to do that and that affects the entire passing game.