Hi Sha, we know about the bug in the profile and we're working on it, though it's not the highest priority at the moment. If you look at the actual comment itself, you'll see the proper number of thumbs.
Donnie (and others), I personally wasn't here when the decision was made to have a thumbs down without requiring an explanation. Having gotten thumbs down myself, I know how frustrating it is to not know why someone thumbed something down. However, I've also seen the positive side -- you can show disagreement with a post, comment, or answer without being required to add to a potential flame war. Craigslist forums work similar, where you can see the number of plus and minus points an individual comment has. Rather than a suggestion having three responses of "this sucks", three downvotes indicates people don't like the idea but do prevent name calling in the comments.
Another thing thumbs down are good for is alerting us to spam or comments that go against our guidelines. We do keep an eye on what is thumbed down, and that's an easy way to call out a potential problem to us.