that picture of cassel is exactly why no one likes him. he doesn’t brace and drive through his throws properly – his front foot is way too close there, and he’s got a floppy back, and as a result he has to arm it in there, resulting in poor accuracy especially in the 10-20y range where good QBs make their money.
note the lean backwards in his torso – proper footwork and more body discipline would allow his core to drive the ball forward rather than having to rely on the bend and snap method like he is there, which results in a much more irregular release point.