Cover Letters?

I have been applying for summer internships and am getting a wee bit tired of writing cover letters. To have a really good cover letter, they all have to be custom, so you can't use the same one over and over. I almost used the below letter out of sheer frustration, but then thought better of it. Wouldn't want to burn any bridges.

Sir/Madam:

You have asked me to provide a cover letter for my application to (company name). Said letter is meant to have the applicant show how the skills and knowledge they possess could be used - usually in respect to your company. However, the irony was not lost, as I read that one of the talents/skills that are desired in this position is a desire to do things "a new way" and to have a "keen understanding of new media," etc.

A cover letter is truly just an ancient trope that should have ceased at the advent of the new millennium (if not the early nineties). In this new age of computers and "new media" all they really do is restate what can be gleaned from the attached resume by a person of average intelligence. They are rarely read by a hiring manager and are generally just extra work.

Is the purpose of having the applicant write something enable the hiring manager to see if they are able to communicate? If this is the reason, I apologize, though this could easily be accomplished - with less annoyance on both sides - by having the candidate write a short essay on a subject related to the company or industry. If this is not the reason for the letter, I must assume it is to continue an obsolete institution for no other reason than: we always have.

Best Regards,

What do you think? Would it burn bridges or scale mountains?