IBM has a female CEO. IBM sponsors the Masters, an event held at Augusta National, a private club that does not allow women to be members. Which means Virginia Rometty can’t join the club that her company pays to prop up.

This isn’t a new story (or a new controversy). And I don’t expect Rometty to make a big deal about this. It’s not her job. She became CEO of a Fortune 500 company not by railing at the glass ceiling but by pushing through it.

IBM, however, could do better.

I was thinking about this again the other day as I was reading Why Boards Need More Women. The article correlates better gender parity to improvements in sales, risk management, and reputation.

But this misses the “why” factors: experience and perspective.

IBM’s 13-member board of directors (excluding the CEO) has an average age of 63 (the youngest board members are 57). There are two women. Old, predominantly male, and predominantly white might reflect Augusta National’s membership, but it doesn’t reflect IBM’s customer base–or it’s employees.

Here’s why diversity matters.

My mom has a friend who worked for a big New York law firm in the mid-1950s right after graduating near the top of her class from the University of Chicago Law School. About once a week, her male colleagues would have lunch with a partner at the club on the penthouse level of the building. (Yes, it was “men only.”) It wasn’t fair–but what was she going to do then? But I know what she’d be pushing for in 2012 if she were on IBM’s board.

Jump ahead just one generation. I’ve seen the glass ceiling, but I’ve largely been immune from its impact. (It helps that I work for myself.) The women who have followed me into the workforce didn’t grow up in a world of gentlemen’s country clubs. You know my perspective. What do you think their reaction might be?

I’m also a business owner. I’m not telling IBM’s board of directors that the company should take a public stand and yank its sponsorship tomorrow. But if I were on that board, I’d be advising company executives to think about what “I’m an IBMer” really means.

Photo by PinkMoose (Flickr).