I think most people do this. It's often striking how many people ask questions that are answered in the linked article.

The Tesla story currently on the front page is a great example of this.

Sometimes I do read the comments without reading the op, but then I won't comment, unless it's something unrelated (like this very comment, for example, even thought in this case I did read the OP).

But yes, there's plenty of "Didn't read the article, but...".