Data point: most freelancers I've been coaching during the last years do /not/ realize they are running a real business. It usually takes a life changing event (birth, or a big tax issue) for them to change their way of doing it, if this changes at all.
Based on various people I've known, that's a great if surprising point. It's actually pretty easy for many to just sort of drift along on the edge for a long time and essentially pretend that everything is good--until it's not. Maybe the client that's 50% of their business up and leaves for whatever reason or, as you say, something happens in their life that makes no savings and no real plan suddenly untenable.
I'm no longer surprised by the disconnect between a great dev/writer/artist/musician and a good business sense. Most freelancers I meet have a great talent in one area - but talent in that area doesn't always mean they know how to market or manage it as a business. It seems so obvious, I agree - but it's a big stumbling point, at least with those I come in contact with.