Dez runs go routes, slants, and fades not because that's what the system dictates, but because he hasn't gained the coaches trust in running anything else. That's the bottom line.
The top echelon guys are more cerebral in their approach to the WR position. Dez is pure physicality. Which is pretty effective, sure.
But when guys use their head AND have the physical element to go along with it (Julio Jones, Calvin Johnson, TO, etc), then you have a special, special talent.
Go ahead, disagree and claim a higher football IQ all you want, but Dez is nowhere close to any of the best WRs in the game.
Teams fear and respect Dez about as much as they do Mike Evans, Benjamin for the Panthers, and other guys who mostly try to bully their opponents