Did it because I want to make a bot to bring top news from HN into my timeline as they arrive, because it's been a bit quiet recently and I need something to play with :p and I didn't want to use a different email to make an account.
Perhaps controversial for , but now you can create multiple accounts under your account (aka personas) that you can use as regular accounts, each with their own profile. The same email is used and you can switch between them under /account/accounts.