I have argued this fact as well about it being in the blockchain. I am fairly technical and can determine how to get at it if I want. Likewise, if the government deems certain things are banned and locks them in a vault. They technically still exist it is just difficult to get to them.
So in effect the crushing hammer blow of a down vote can be very similar to shoving something in a vault. Many people will be unable to view it. Perhaps someone will make a reversesteemit.com or something where the trending page and popularity is 100% the opposite. You'd have to wade through a ton of spam but you might see these posts that were splattered. The problem is this shouldn't be being done for opinion.
Except it doesn't just affect that piece of text. It harms the author.