You are correct; you do not know..:-)
As for the unfairly maligned Arthur Wordsmith giving away trade secrets, well, whether working in a confidential market sector or not, it might be better not to tell him any secrets in the first place. And, I'm not quite sure how the decision to include or not include an author biog is going to turn the writer towards industrial espionage!
The discussion here is based on how to credit articles provided by freelancers. The issue of whether a 'named' writer can increase traffic to your site is another matter methinks and likely worthy of a new thread...
It's not necessary to credit those that help your site become a success. They can be anonymous 'staff writers' should one so desire it. I believe it really helps if you can show that the writer knows what they're talking about. Credibility and trust counts and is essential if your site depends on return visitors. After all an article is a unique means of communicating with an individual, and maybe lots of them.
Lonely Planet is a great example of a brand that has become trusted because of the quality of it's content and the fact that they certainly used to hype up the names and profiles of the contributors a few years ago. They built their reputation on the reputations of the quality writers they commissioned - a wonderful job done.