I have to say I usually don't read the cover letter either, and wouldn't care too much if they didn't have one, except for new graduates, or where this is their 2nd job where I would like to see a modicum of research on their part.

But usually a cover letter encourages the writer to tell me what they _think_ I want to hear, but not what I really want to know - which the CV usually does much better.

Which means they are often sycophantic and a bit embarrassing - and I usually have too much respect for the people I want to interview to expose them to that :)