There are two reactions to diagramming a sentence: Love and hate.
I love diagramming sentences, and I heard several students today mentioning how cool it is and how they "get" it. Honestly, I don't care if everyone gets it or not. As long as they can find the basic building blocks of any given sentence (simple subject and simple predicate -- or verb), I am a happy, happy person. But, I also believe that to be better writers, they must first learn the rules before they start breaking them.
After scaring the buhjeezus out of them today by ramping up and ramping up and ramping up some more about parsing sentences, I told the kiddos to go home and tell their parents what they're doing in English class. You see, if you remember diagramming, you'll have one of two reactions and nothing else in between. You will either raise your hands in joy and rejoice in the diagram that will become your parsed sentence, or you will start twitching uncontrollably.
One of my co-teachers is a twitcher. I love diagramming and have a hard time understanding how anyone cannot enjoy working a sentences to its bare naked core.
Tonight they have diagramming homework. We will see how many show up believing they are Einstein and how many show up just looking like him all frazzled and spent.