Pickett would be doing the same thing if he was playing because Matt Canada's offense is run that way.
Steelers do not challenge the middle of the field. Most of the throws are on the boundaries or checkdowns. Trubisky only threw 3 passes over the middle last week that were over 8 yards. Pickens only ran go routes or fades. Diontae was never targeted in the middle of the field.
I like Pickett and think he'll get his shot sooner than later but it's going to be rinse and repeat until Canada is shown the door.