The average consumer isn't using a standalone camera for their, um, bedroom work... they're using their phone. I'm sure there are some people who get into that sort of stuff enough to use high quality camera gear, but again - vanishingly small niche market.

As for kids... most people are just posting it straight to Facebook anyway. Again, some might care about privacy, but not enough to make it a real premium feature, I suspect.

Naturally people want to pick and choose which photos they share, but that doesn't mean they are worried enough about the ones they didn't choose falling into the wrong hands to pay a premium and put up with cumbersome decryption procedures - they just don't like those photos as much.