Write your pass code on a piece of paper, put it in an envelope, and staple the envelope to your will and deposit it with your lawyer. Nothing prevents you from telling loved ones your pass code.

They give you the choice.

Isn't this problem already solved in the non-tech world through a last will and testament or a bank lockbox which contains passwords you want people to have in the event of your death?

I'm not sure it's a perfect solution but might be better than counting on someone to reverse engineer or hack into your phone.

If you're serious about encryption you should always have a backup key somewhere... unless you want a single point of failure (you). Both should be an option.

Of course we want! Then only I am in the power to chose who can access my personal data. What forbids you from leaving your private keys and passcodes to the next of a kin? Furthermore, if information in your phone is important to more people than you only (family photos etc.), it should be backed up somewhere else anyway, you don't keep all eggs in a single basket. The real problem is that cryptography is very powerful tool and we need to educate people how to use it properly. Of course, it's naive to hope that it can be done overnight, but small, incremental changes might be done imho. For example, before asking user to create it's master passcode, emphasize in big, bold letters, that it's your reponsibility to keep this password safe and accessible, because if you lost it, there's nothing can be done to bypass it. Keeping user key/password backup (aka MS style) is a sloppy security tactics.

If I die I don't want anyone accessing my phone.