I suspect, perhaps pessimistically, that the reason that I do not program my PC like I programmed my Spectrum is not to do with the technology per se: rather it is due to the propensity for creative construction lying predominantly in a) the naivety, and b) the abundance of time peculiar to childhood.
Image from PKNTS.com
It is in the child's market that I am sure we can see the best innovation - for one thing it seems to inspire toy designers in a way that adult gadgets don't. For example PKNTS's Alle Meine Klange - a modular sound toy that Make reported on recently - looks like great fun: a simple, highly potent platform for playing with electronic sounds between computer and tangible blocks. Lego, Meccano, Quadro were all kits that I and countless others revelled in as children and I think are responsible for many people's DIY and 'hacking' tendencies, not to mention simple mechanical knowledge, a theory that is borne out by the prevalence of these kits in design studios generally!
The wikipedia article on constructionism as a learning theory postulates that:
"learning is an active process wherein learners are actively constructing mental models and theories of the world around them. Constructionism holds that learning can happen most effectively when people are actively making things in the real world."
Clearly the trick to designing products that people love to play with right through into adulthood, and can still apply, is in building a product platform, a system, that users can bend to their own needs, and that doesn't require huge amounts of skill or experience. Which is basically what is slowly happening now in industrial design thanks to CAD, the web, and digital fabrication.