the current logo that you commonly see as bitcoin logo is not designed by Satoshi, the idea is from his original design and idea but it has changed. if you think it is bad then feel free to give a suggestion or if you can design one, if it is good enough then we will use that as the logo.


edit: the original design was not even a single "B" it was a "BC" according to this picture:
(you can see the logo on top left corner)