Some people maliciously or accidentally provide another's email address, and now that person is getting your unsolicited commercial email (i.e., spam). And now

Some people maliciously or accidentally provide another's email address, and now that person is getting your unsolicited commercial email (i.e., spam). And now they must actively do something to try to get off the list. Double opt-in means by doing nothing they will only receive your original confirmation email. It's not a matter of being crazy. It's a matter of being considerate.