Spearing = leading with your head.
Wilson doesnt really lead with his head, he just punishes defenseless receivers.
But he's been called for spearing before when he's led with his shoulder. The "defenseless receiver" rule is one of the worst ever concocted by the NFL. Punishing receivers has long been one of the most effective ways to play pass defense.
It's like the NBA writing a new rule that if a player is fouled in the paint going to the basket he gets 5 to make 4.