I'm gonna have to agree with this assessment.
Look, I'm a lifelong, diehard Bills fan. Shanahan did nothing with Trey Lance that we haven't seen with the use of Josh Allen under Sean McDermott, Brian Daboll, and now Ken Dorsey. Allen was our leading rusher in the season opener against the Rams.
Injuries are part of the game. In the age of mobile quarterbacks, an injury like Lance's is part of the risk assessment. Neither Kyler Murray nor Lamar Jackson would be the players that they are without designed runs. That said, this is why the flack that Shanahan is getting is such bullshit. Lamar Jackson isn't a particularly big guy, and Kyler Murray is a particularly small guy. Their coaches should be aware of the toll it takes when they take hits.
Josh Allen is a 6'5", 250 pound monster of a human being. He's bigger than most linebackers. Hell, he stiff-armed Aaron Donald. Trey Lance is a similarly big dude. The Niners want to use him similarly to the way the Bills have been using Allen.
Knock on wood - my Bills have been lucky. Lance's injury isn't Shanahan's fault.