The trouble with statements like 'for the average xyz user' is: 1. 50% of your users won't have their needs met - that's a large proportion assuming a uniform

The trouble with statements like 'for the average xyz user' is: 1. 50% of your users won't have their needs met - that's a large proportion assuming a uniform distribution 2. We can't be sure a uniform distribution in the first place is appropriate 3. If we're going to assume an average user then why don't we assume an average phone too: If the average user gets by without something today then why bother building it as a new feature? In the end a product should not be designed for an average user. It should be designed for a well defined audience who's needs will met well by the product. If you're going to bother with fancy biometric tech as a feature and selling point then you're clearly NOT aiming at the average user who couldn't care less...