I thought it was an interesting thing to think about, though--why the privacy aspect seemed so much more important w/ an e-mail newsletter than w/ a print magazine.
I think it may have something to do with the lack of collected data on emails.
With addresses, unless you have specifically requested that they do *not* put your number/address in the book, it goes in basically a public domain.
With emails, it's the exact opposite. In order for anyone to know that this is *your* email, you have to give it to them/have signed up for something, ect.
With emails, you can make one and only give it out to specific people, such as having one for business, one for personal, one for kid's teachers and activities. With addresses, there's just one (unless you use a P.O. Box) and it's a collection of everything. Junk, bills, W-2's, possibly paychecks, personal letters, magazines, and just about anything else you can think of. There's no way to say, "Bills should go in this mailbox, letters in this one, junk in this one."
So for emails, it sometimes just comes off as a lot more personal.
Which, thinking about it, is strange, since giving out an email means they know random letters attached with an @ sign at a random domain that has nothing to do with you. Giving out addresses means that they know where that person lives or works.
I will admit that reading over this, I had the same issue you did, though. I can totally see myself giving my friends magazine subscriptions. But I'd feel the need to ask before I did an email newsletter.