Hi John,
I agree that millions of people choose to spend time on Facebook, as well as games and other recreational activities like computer games. My guess is that, for most people, these activities often don't feel like work, while contributing to Wikimedia often feels like work. I think that are technical and social factors that contribute to Wikimedia activity feeling like it requires more effort and/or is less rewarding than the alternatives.
If we had enough human and financial resources, there are changes that could be made to improve the user experience and to make the rules be easier to learn and to understand.
I think that making the rules be easier to learn and to understand are more realistic goals than reducing the complexity of the rules.
Also, I think that there may be design and technical changes that could be made to improve the intuitiveness of the user experience, and to improve the social experience.
I'm hoping that my training project will help with users' learning and understanding of the rules and the interface. However, this is a long term project.
Design improvements made to the interface would be good if they could be done well and if WMF could afford them, but my guess is that such changes will be incremental over many years and that giants like Google will always be in the lead party because they can afford to spend so much more money and have so many more staff to make their sites be user-friendly and to optimize their sites for the user behaviors that they want to foster.
To a certain extent, Google and other large consumer-oriented organizations compete with WMF for the time of consumers, although one can hope that they will eventually decide that Wikimedia content is valuable enough to them that they want to support the community far more than they do at the moment.
I wish that I had reasons to be more optimistic about the human resources and financial situation in Wikimedia. If you can think of any, I would like to hear them. :)