Not saying this won’t have any negative effects on people, however I think it’s a little premature to guess at what it will be like. About 3/4 of the article is commenting what it will do to men when we find out only at the end women are the majority of users.
I can think of alternatives. For example, the server could keep the user’s private key, encrypted with a passphrase that the user must have. So key loss wouldn’t be an issue. (Yes, passphrase loss might, but there are lots of ways to keep those safely already, compared to key material which is difficult to handle.)