All of the debit cards I've gotten from traditional B&M banks have let me activate them at an ATM. Only my current bank, which does not have physical locations, doesn't give me that option. I assume it's because they let you use ATMs from partner banks but don't have their own.
Ah I just want to clarify, we aren't "required" to activate at an ATM. I'm just saying that we are able to activate a card without having to go to an ATM. I'm sure going to an ATM is an option as well.