What really bothers me is that most of time when the date of birth is asked it is done as a way to determine some age criteria. The same could be achieved simply asking "are you older than N years old? [Yes] or [No]".

For example, I want to buy Quake on the Nintendo eShop. The website wants to know my age in order to show me a age restricted game. So it will always ask me the age same question even if I have already answered hundred of times. So does Steam and many other websites. Is this a by-product of some compliance or self-regulatory requirement like ESRB?

If not, it would make much more sense to just ask a yes/no question for the age criteria. Usually this argument is answered with "what about fraud?". Well, asking the birthday is no guarantee at all that the birthday is correct. It only adds friction.

As a small revenge I always use an absurdly old birth date on these forms. This way if they are collecting this data, my input will be discarded or pollute their datasets.