Can't I just look to the left?

So, I'm registering for the JREF forums, and I get to the part where it asks me for my e-mail address. I enter it in, and immediately to the right is another box asking me for my e-mail address for "confirmation." Having seen this many times before, I resort to my old "shift-home, ctrl-C, tab, ctrl-V" routine and proceed. Asking for confirmation of an e-mail address is standard practice these days, but how is it that no one ever questions the purpose of it?

This whole confirmation thing in general started with selecting passwords. Generally, passwords are obscured as you type them (in case someone is looking over your shoulder), looking like a series of circles or asterisks. This means that you can't look back at it and confirm you put it in just how you wanted it, so one slip up could prevent you from ever remembering it. The solution to this was to ask people to put in their passwords twice, so if there was a slip-up in one, they'd get a chance to try again.

When it became common to ask for e-mail addresses as part of registration, they were similarly obscured for privacy. Then, since they were obscured, they put in the same second entry for confirmation. Since then, however, obscuring the e-mail address has fallen out of favor (privacy isn't as critical as security), so you can now see it clearly as you type it. But when this change was made, whoever was in charge apparently forgot to remove the confirmation box (or didn't know its purpose, or something), so that stayed.

The result is that all of the current forms follow the trend and ask for your e-mail address twice, and you have to type it twice in plain view. Them being too dumb to remove the confirmation box results in the implication that we're too dumb to look two inches (5cm if you prefer) to the left and check for ourselves that we got it right.

There are a few designers who have figured this out and don't bother with it, but surprisingly the JREF wasn't skeptical about this particular trend.