Have this conversation all the time. People can barely manage bank accounts. 

 Oh, you lost your private key backup and now your kids can’t go to college? Guess you’re shit outta luck, my dude.

This level of responsibility is not for everyone. 

 There is no way around the educational hurdle of the great mass of people to learning to manage private keys. 

 Timed transactions which we need for inheritance would also maybe help make this less daunting for people. Could make it so if you lose your keys, your money gets sent to a trusted exchange or bank you use 

 (or a friend/family obv) 

 "Custodians are a feature not a bug" thinking will result in regulatory capture of the network.

People have to man up and learn to manage their own private keys.

If not to manage their own money,
To prove their own identity on an online world 

 Most people don't want to be responsible, period. I don't think there's much of a solution for that.