There are some exceptions to this. Notably, Amazon is ruthless in enforcement of their "One Person, One Account" policy (worded not so eloquently in their official terms).
If you lose access to your Amazon account and open a new account, there's a non-trivial chance they shut it down without explanation. If your account ever participated in the marketplace from a seller side, then this policy is even more ruthlessly enforced.
Which means... email address verification is necessary for Amazon to at least guard against type-o's and other common form data-entry errors.
Is this policy for a specific kind of Amazon account? I didn't recall seeing anything in the TOS, and they appear to have first class support for people with multiple accounts.
If you lose access to your Amazon account and open a new account, there's a non-trivial chance they shut it down without explanation. If your account ever participated in the marketplace from a seller side, then this policy is even more ruthlessly enforced.
Which means... email address verification is necessary for Amazon to at least guard against type-o's and other common form data-entry errors.