I posted in the thread on the unschooling board about my ds's writing. In our unschooling, a lack of writing prowess has not been a problem until adolescence.
Writing is required in school for evaluation purposes. That's why it's expected, and normal, for 2nd-graders to write reasonably legibly and easily. A second grade teacher can't hold individual conversations with 21 different students to gauge each child's understanding of the main ideas presented in the unit on food chains. For homeschooled kids verbal interaction is typically more natural, more enjoyable and easier. And a parent can get a very robust picture of her child's understanding without anything being written down.
Writing in the real world is required for meaningful communication like job applications, political activism, maintaining friendships over distance, advocacy, some careers... all worthy things, but things that don't really kick in much until the teen years. By then interest in and facility with keyboarding had kicked in for my kids and hand-writing was a skill with limited application. My girls had mastered handwriting anyway, though. My eldest dd got it down around age 8.5 when she began journaling privately; it came quickly and easily for her. My middle dd had a more gradual progression between ages 9 and 11, but didn't have to work much at it. She just used a pen more as time went on and progressed to a point of ease.
Ds is a different kettle of fish. He not only had a late start like his sisters, plus some serious perfectionist issues, but when he got to the point around age 11-12 of wanting to work on his handwriting, the systematic work did not make the skill much easier. His letter formation became more regular and conventional and certainly very neat, but he never developed ease. He's the one who ended up designated dysgraphic through an evaluation at age 14. He writes beautifully with a computer, but hand-writing more than a couple of sentences is difficult for him and interferes with his thought processes. It has been a bit of an issue for him to deal with since entering school, but not a difficult one. His "adaptive technology" is just a laptop, and in 10th grade he's not the only kid to tote one around in his backpack.
I disagree a bit with Roar about sooner-than-later intervention. (We don't disagree often!) I've never seen anything to suggest that early intervention in dysgraphia does anything to help improve outcomes, at least beyond minimizing the negative emotional baggage of being "behind in school," something which obviously doesn't apply to unschooled kids. Motivation, meaningfulness and maturity can make it a heck of a lot easier for a child to deal with the practice required to develop a basic facility with handwriting. At age 7, a year of daily work on cursive would have destroyed my ds's relationship with me and his confidence. At age 12, the work was tolerated matter-of-factly and motivated mostly by his own desire for mastery -- and he had more stamina, more frustration tolerance and more tools for efficient problem-solving, so progress, such as it was, likely occurred considerably faster.