The point of badges is to encourage good behavior, not random chance. Take a screenshot, throw a party, do what you must to celebrate the occasion (I know I did a dance when I hit 2999 reputation exactly), but there's no reason the system has to reward you for something that's simply chance or numeric manipulation. There's nothing good encouraged by hitting a specific number.
Numeric manipulation is the primary reason that this badge would actually be a bad idea. People who are nearing the number of desire would use crafty downvotes and other measures to ensure that they get at the exact number they want, which is casting votes on the motivation of getting reputation to a specific level rather than to mark the usefulness (or lack thereof) of posts.