The fact of the matter is, the up/down vote options are there and no one is stopping anyone from using them. The only thing that can be done is for the mods to comment on it (I don't personally like editing it, even though we can as it is too heavy of a modification) and for others to downvote. If people want to upvote it enough and there are no flags against the answer, there is no valid reason to delete/edit it.
It only further shows that this site is community driven. If the community rewards this, then people won't learn. If the community flags and downvotes, it shows that it is unacceptable and people will learn that way. Sure downvoting an answer comes at a cost of a whopping -1 rep, it is a further consequence for the answerer, as well as this rep lost by downvoting is easily made up by suggesting an edit and having it approved (it results in a +1 gain)
Also, as my fellow mods have pointed out, the question and answer were both from when the site was merely a week old, therefore upvotes abound to encourage people to post more Q&A on the site.