Don't believe that warranted a downvote to be honest. /u/nebraska wasn't being rude to the person making the snap, he was giving his guidelines to the people who are reading this snap at the moment. And it's a good advice as far as I'm concerned.
So in this instance you downvoted someone for disagreeing with them, since that user was not using hate speech or being offensive.
I was going to make a remark about that as well, but I decided against it because I believe /u/nebraska's comment falls in a grey area.
The comment may not be directly rude or offensive, but it is not very hospitable either.
I believe he could have delivered his advice more tactfully, without the kind of tone that often discourages people from posting over at that other website. Not that /u/nebraska didn't have good intentions or didn't contribute to the conversation at all, hence the grey area. I personally feel like this is a situation in which either actions — upvoting or downvoting — are equally justified. Just my two cents. :)
hehe i thought exactly the same and was wondering what /u/kvn was talking about. :) Well i think you see it both ways, only /u/nebraska can tell what he meant.