The primary purpose of the Stack Exchange sites is to collect knowledge in a Q&A style. Badges are used on the site to entice users into performing tasks that are mostly beneficial to the system as a whole.
The result of these tasks is what benefits the network
, while all the badges really are, is noise!
Therefore I don't see that the majority of the community will ever want this feature implemented. Having said that, and as I have mentioned in a comment above, you could always propose that this list of badges be displayed next to the corresponding question and/or answer on the actual users profile page.
Bear in mind though that even the latter suggestion is bound to get shot down solely because of the server overhead and processing this swanky new pile of
noises badges will contribute!