It’s true that you used to be able to like/unlike a blog after a while, but what if someone writes a really good blog, then gets hacked, the blog gets replaced with troll stuff, and people suddenly come in and look at it, and say, this is what the community likes?
Probably won’t ever happen, but I don’t see why there’s a limit on up/down voting either. :p
Let me tell you, if I ever hacked vutales, the least I would do is change a blog.
That’s the point, if you ever decide to dislike a blog, because you don’t understand it or anything, and something changes, like, the blog is edited or suddenly you understand it, you should be able to change your mind. And albeit you are right, there is a low chance that you want to change your choice, it should not restrict you. It just adds unnecessary complexity to the database table and the source code.