On written ineptitude

How can you write so
badly? I don’t understand.
Worst. Grammar. Evar.

I don't understand how some people can be so inept when it comes to written language. I've been revising these guides for this guy for months, hand holding constantly... and he still doesn't get the concept of "don't use technical terms. Use informal second person constructs. These are guides for low level users - you need to tell them 'and next you do this. Now you do this' if they're going to get it." I give up. I'm just going to write the final draft myself, it'll be so much less painful.

Edit - oh the irony! That I can't manage syllables, when I'm bitching about grammar!