Why dissaprove a comment when you can edit it?
The person created a comment on your post and you did not like. No matter the reason.
You got a comment from elsewhere in the world (with a distant IP) that you can edit and insert as many links and keywords as you want.
I mean, if the guy doesn't care, does not have the ability or knowledge, and writes anything that does not fit to your article, will he be bothered if you edit his stuff?
Why disaprove that? Why lose the opportunity?