Answer:
As a matter of policy, some banks do not give debit or ATM cards to fiduciaries, including representative payees. Their rationale is that one of a fiduciary's key responsibilities is to provide an accounting for their use of the funds and electronic transactions may diminish their ability to do so.
Their policy is not dictated by law or regulation, it's simply a decision they have made.
As a complete aside, Regulation E generally does not apply to fiduciary accounts.
First published on BankersOnline.com 5/20/13.