Yeah, although offchain things are an "anyone can do job"... and why gets neglected on-chain. Also, because it would involve basically integrating with everything, it creates a bit of a struggle for everyone.
But definitely creating a hive account should be made easy peasy... it could be even an automatic thing that sends the private key to the email. And then drive the person through a more elaborate process (once ready and returning) for changing keys, etc.
At the same time, this might create many stale accounts... and a recycling process should exist... like, accounts with 1 broadcast, could be interpreted as, not yet taken. And perhaps avoid an infinite amount of accounts lost thing.
Food for lunch time thoughts... (for me).