I think it's amusing that you can ask for word suggestions and get a list of 50 things to do in the outdoors, as though it's one or the other 
There's nothing wrong with a child do writing practise if they are so inclined, IME you can't force a child to do something they don't wish to.
I'm not sure 'unteaching' - anything they learn before will surely be in addition to what they pick up at school. My son deosnt enjoy writing that much, and doesn't feel comfortable holding a pen correctly yet so I tell him the way but don't force him and let him have a go anyway when he fancies it with no pressure; he nowhere near forms letters correctly, I figure he will fine tune that at school, but I'm not going to stop him trying when he actually wants to. We also do loads of Lego and writing in sand with fingers etc
I learned to read before school in whatever haphazard way my mother encouraged it, not a phonic in sight (or earshot) I don't suppose, I didn't have to unlearn anything, I just carried on learning until I got my degree without realising I was doing it 'wrong' 
It's counter productive to the idea of education being enjoyable that so many people separate 'writing' and 'reading' from 'all the fun stuff'. A child can have fun learning to write simple words as well as riding a bike, it depends on the inclination of the child, surely.