Not quite, it gets you about 90% there. Even with a grammar to use off the shelf, you still need to write queries to make use of it for highlighting, text object selection, auto indenting, etc. These have so far been particular to the editor.
This is surely just the bias of those willing to make a comment one way or the other. If you are so-so about it, you probably don't make the effort to make a comment.
This stuck out to me too. Terraform absolutely does check the current reality of the state and applies changes to do what the HCL tells is to. They are either using terraform in a really weird way, or this article was written by someone that doesn't actually run terraform themselves.