Imagine giving that away to the hackers, blaggers and spammers of the world.
No, you don't have to be a celebrity to be hacked today. There are a lot of buyers willing to pay millions of dollars to buy our data, and imagine the price of some personal email juice. For details I'd refer you to the real experts, Snowden, Assange.
Secondly, you are tied to your company email address (or ISP). So in future if you move out and change company, your username still identifies you with your old org.
Tell us if you need your username changed
The cyber weirdos don't plan to slow down/retire any soon. If you've just realized what I'm talking about, we can change it for you in a jiffy.