There's certainly something to be said for that. I like people who are forthright.
But this is a pseudonymous forum. And more than that, I think the founders and current admins place some value on user privacy. I don't think it necessarily indicates deceit to use an undisclosed alt account, and where it does, it's not necessarily meaningful.
Engaging in fraud under that pretense is another matter entirely. But frauds don't announce their alts, so it's a moot point.