I was the one who cast the first downvote, I don't know how many it got since then because the answer is now deleted, but I cast the first one.
Why did I downvote that post? Because I believe an answer should answer the question. This "answer" certainly did not answer the question. The original content of the post simply contained:
This is not an answer. This is:
The help center page for Why and how are some answers deleted? states:
Answers that do not fundamentally answer the question may be removed. This includes answers that are:
- barely more than a link to an external site
(Emphasis original)
Therefor I downvoted it because this answer is not useful, it would be a useful comment not a useful answer. Although I didn't flag the answer for removal I would have done so if I had thought about it.