I think you underestimate the average Joe's desire to save a few dollars... The key barriers I see are having to install special software and getting to grips with Bitcoin.
Perhaps it is possible to ship a client with some default blacklisting of certain products, sellers etc, if a person wants to avoid stumbling by accident across such stuff. (Maybe even such blacklists would become updated and mandated by law.)
You need to insulate the user from the Bitcoin transaction entirely. It should look to the user like they're paying in local currency. Unfortunately, we're not there yet. We know how to create an automated p2p currency exchange, we think. But nobody's done it yet.
I read it more along the lines of "some folks and I have come up with a reasonable solution, but it's nowhere near production ready so no one would want to test it."
Perhaps it is possible to ship a client with some default blacklisting of certain products, sellers etc, if a person wants to avoid stumbling by accident across such stuff. (Maybe even such blacklists would become updated and mandated by law.)