Here's my problem with unschooling
children's learning is never self directed, not fully, they can only chose from the options they are exposed to.
So if you live on a farm where your parents daily activities include: tending livestock, butchering, preserving, planting food, harvesting, building/repairing buildings, carpentry, thatching, spinning own wool etc.
.. then the kids'll probably chose something valuable to learn out of all the opportunites they're exposed to
Likewise, if your parents are carnies, and they and their community are doing business, engineering/repairs, logistics, serving the public etc.. again, lots of valuable lessons going on in your environment for you to chose from.
If your mum mostly blogs/facebooks and looks up juicing on youtube from a 1 bed flat, and your dad does a bit of yoga.. your "self directed learning" is going to be pretty limited!