You're not the only one to have expressed this attitude but I find it strange. How long does it take you to write 140 characters or less? Also, unless people are actively following you you are not "spamming" them.

Your summary of what Twitter is good for is accurate as far as it goes but what you are missing is that, when they are timely and from interesting people, those small bits of information can be valuable.

I follow around 200 low-volume people on Twitter with similar interests to my own (machine learning, maths, stats, Clojure, ambient music). The number of times I have got useful advice and heads-up on recent articles, events and releases makes Twitter worthwhile the small attentional overhead I give it. On top of that, there is a nice sense of community that has built up over time.

Dismissing something based on its functionality alone without having used it means you won't experience the myriad ways people make use of that functionality. Emergent behaviour is powerful and difficult to predict.

"Computers? Sure, they're useful for quickly processing numbers represented in binary but it's not like they are designed for doing really complex things."