They never ever seem to have a button that says "DENY VERIFICATION " or "Nope, that's not me"
Small shops I never heard of and big, international, well known businesses - they never have a "Do not approve / register / verify" button.
(Today I just got half a dozen emails from PayPal - apparently somebody is using my email address to register. Based on subsequent emails, even though this email was never verified, they continue to do their business and register. PayPal won't let me deny usage of my email, submit a ticket, or contact support for help without logging in, which obviously I cannot and do not want to do - I'm not to the one who got registered!).
So what is the point in email verification emails, if there's no way to deny it / indicate "Nope that's not me, don't do it"?
I suspect the reason for not having an explicit 'deny' button is based on cost-benefit analysis. The benefits might be limited to 1. Improved user satisfaction, and 2. Minimise the risk that a user might accidentally click the confirmation link. But I suspect these aren't enough to outweigh the extra (arguably unnecessary) effort of implementing it.