And what would a businessman know about ethics, anyway? The most any of them have heard the subject discussed is in the
first two minutes of Miller's Crossing.
I seriously doubt there is a Business Ethics major available in any major college or university in the U.S. Most schools don't teach such a thing at all. There is no recognized authority that watches over businessmen, like the AMA or a state bar does. And if there were, it would be immediately penetrated and turned as quickly as the Iraqi Army was.
Business is the art of
unethically separating people from their money. Sure, you might be an honest businessman, but you do the bidding of an evil businessman, or you sit on a town council with them, or you're a member of the Chamber of Commerce with them, or you back a political party that is controlled by them, and so on.
Making business honest will be a multi-generational project that is designed to change our entire culture and which will be fought against a wealthier and more powerful adversary. Asking businessmen to sign a pledge saying they'll be honest is just like asking a hormone-amped teenager not to have sex--all it does is temporarily divert your attention from the bad behavior until the consequences are obvious.
Edit: Just to underscore what I mean, do you know how many Ethics & Compliance Officer Association members there are nationwide?
One thousand, one hundred. That's as close to zero as you can get in the U.S., where that many people vote for Yoda as President each term.