It seems many new users are using their email address as their username. In a public community where usernames are visible, I think it's a bad precedent.
I tend to agree BUT keep in mind that in a user profile here on Vanilla, a user can choose to reveal their e-mail address for all to see. I believe it is hidden by default
At least a new user should be warned (when creating their account) that their "username" on this site will be their public handle, and that it will therefore be visible to everyone. Many companies' web sites I've seen in the last year are moving to combine username (login name) and email address. But the ones I've noticed have all been sites where the user isn't posting publicly. So the trend is that people are developing the habit of using their email address as a username to keep things simple. For a discussion board site like this one, I'd prefer to have a field called "screen name" for the public-facing name, which might help to distinguish its role from a "username" used to sign in.
RiverView: US Quicken Premier Subscriber on Windows 10. Using Quicken on Windows since 2006.