A metaphor is an important tool used to convey complicated ideas to the general public. Since the beginning of Bitcoin (and especially Bitshares) we've had a very hard time coming up with a simple way to convey the core essence of what is being created here. Is it a company, community, bank or a government? The truth is, Bitshares has the potential to be all of these things. So what do all of these things have in common? What is their essence?
ANSWER: They can all be described as types of operating systems.
I'd like to conduct a fun little experiment. Pretend like you're chatting with a relatively tech savvy person and he asks you "what is bitshares?" In your own words, describe Bitshares using the FinancialOS metaphor as your foundation.
Stan is probably got the best answer, it depends on what works best for your target audience.
Your ANSWER is lost on the audience you defined in your first sentence. I interface with the general public as a computer expert offering tech services and training in my local community. I can tell you that even those at the 90th percentile of tech knowledge around here don't grasp what an operating system does, anymore than a typical housewife understands the role of an air conditioning compressor in her car or home.
"Tech Savvy" is actually a fairly broad term. To all but a very, very small few members of this community, "operating system" is a highly descriptive analogy, a metaphor that fits well.
The key to using any analogy is it's suitability to the target audience. I have had to explain computer issues to a very wide range of people, and when I do I often have to find the right analogy until I see the light bulb go on over their head. Car analogies work well with most men, but for women it's much harder to come up with common examples of systems they are familiar with. If car / mechanical analogies don't click with them, I usually think about churches, institutions or some type of group organization and the control points in them and how things get done or resources managed. Things work well for men, groups work better for women.