You can edit old posts, which is tracked. You can't 'delete' accounts or posts via the steemit front end.

Reread my OP --

add a 'delete' function that blots out entries into the STEEM blockchain so it doesn't appear on their front-ends.

I said nothing about "delete from the blockchain", which is an inappropriate use of double quotations, since I never said any such thing.

See pic related when you attempt to open @thedarkoverlord account via steemit front-end -- you can't do this as a normal account. Why not?