I disagree strongly. Loads of people I've spoken to don't understand what to use Wave for. Those I've worked on projects with who have used it for something real, rather than just a conversation, quickly grasp how useful it is for collaborative projects.
It shouldn't have been marketed as "for the public", at least not at first. Much like mobile phones gained traction in the corporate world, Wave could well have had a similar story, given the time and marketing.