I’m not sure what’s going on out there, but more and more I hear parents say that when their child (typically a boy) is resistant to school, the resistance is linked to anguish (hatred) of performing any type of writing.   

Writing is painstaking. Trying to find the right words, revising your product, thinking about how your words sound, takes time. There is almost never instant gratification. That pencil in the hand thing can really make your hand ache.
At home, the average boy spends hours a day pressing buttons playing video games. Virtually nothing they are doing in the course of their day lends itself to being competent with writing. They have a very hard time tolerating frustration.
Last week there were two boys that I interacted with who stood out in my mind as typical of the legions of those who are writing resistant.
The first one, Holden, is 7 years old. Holden spends large chunks of his day on his iPad, playing Angry Birds or something.  As his mother had told me, whenever Holden is asked to write, he has melt downs. When I greeted him and his mother in the waiting room, Holden could not bother to look up from his iPad. His mother was a bit sheepish when he didn’t look up, but said nothing to him. 
In the second scenario, Alex, a 15 year old, tenth grader is a major video game player who has little interest in anything else. Writing (and reading) seem like activities from a distant century to him. Similar to Holden but in a much larger body, he has a teen version of a tantrum whenever he has to perform difficult academic tasks.
From where I sit, the boys are having a very hard time facing a reality that is not instantly gratifying.  I know it’s their world, and iPads certainly trump pens and pencils (or even typing on the keyboard), but you need to carve out time to get them off their screens.   
They need to start coping better with frustration. Make it positive, not a punishment. Find ways to reinforce good effort and not melting down.