This is a very timely post. Every single person I have preached the Steem Gospel to has had the first question: "but where does the money come from?" What they are really asking is "why do these fake digital tokens have value?" You make a lot of great points here, and I especially think you are right on the mark that many people would possibly be willing to pay minimal use fees to maintain sufficient SP to participate, although my feeling is that through casual typical use, most users will probably be able to maintain sufficient SP to still use the network. Great post!