Did you happen to try actually assigning one of those IPv6 addresses to your PC? Just as with IPv4, if you don't designate which public IP address to send packets from (out of the 2**80 6to4 addresses available to you) you're not going to get anywhere. IPv6 routing via 6to4 is trivial to configure on any modern system possessing a public IPv4 address, but you do have to put a modest effort into setting it up.
DJB's proposal to make all public IPv4 addresses directly routable as IPv6 addresses would save a trivial amount of reconfiguration (the easy part) in the short term, while IPv4 addresses are still dominant. It would not avoid the necessity of updating all existing OS and application software, routing hardware, and address-aware network protocols, scripts, etc. to deal with the longer addresses, which is the real bottleneck standing in the way of IPv6 adoption.