Why was this down voted?
If you've really got a problem with ignorance, do the grown-up thing and attack the ignorance rather than the person.
A wildly ignorant comment (that could be remedied by a simple reading of the comments on this story) probably deserves downvotes as it doesn't add to the discussion at hand at all.
That said, this whole comment section probably deserves a big downvote as it is largely not very good from top to bottom.
It reduces the ignorance in those who read the comments and draw conclusions from what is upvoted and what is downvoted (even though most people won't admit that they do it even to themselves).