Rating expresses an opinion.  

While I often do both, frequently I only do one or the other.  

I gave up 3s after I saw how they can function as damning with faint praise.  And since they can also be given by accident, If I MEAN to damn with faint praise, better I should write a comment that DOES that.  

And 2s mean something is wrong with the comment.  But usually it is better I should say what, or just give a 1 and be done with it.  

And of course 0s are for action, just like the RECOMMEND.  

The point being most things I don't rate at all.  Reading a blog is not like being a schoolteacher!  

The Fates are kind.