The decision by co-founder Jerry Yang to resign from the Yahoo board is as sad as it is overdue.

No matter how rudderless Yahoo had become in recent years, Yang deservedly remains a Silicon Valley icon. He was there at the start of the Internet era, along with co-founder David Filo, building one of the first great Web businesses. It is a company that generated millions of dollars in wealth for founders and employees, created thousands of jobs, and helped pioneer the idea that the Web could be a place where businesses could be built.

In short, it’s nothing to sneer at. And if things had gone differently, it would be a career that people would be exulting today instead of softly mocking.

Had Yang taken this step several years ago, as many suggested, he might have moved into the role of Valley elder statesman. There could have been a graceful pivot to serving as a mentor or start-up advisor, angel investor or venture capitalist. Or perhaps even starting his own business. One could imagine him following the path that another Internet wunderkind Marc Andreessen has take to a new kind of prominence.

Instead, Yang made the ill-advised decision to try to fix an ailing Yahoo back in 2007 and became CEO. It was a short stint, but coincided with a hostile takeover bid from Microsoft that Yang helped thwart. In the mind of many investors, Yang will forever be villified as the person who lost them billions of dollars.

Yahoo continued to drift under his successor, Carol Bartz, and during the many months it took to find a new CEO after she was fired last summer. Meanwhile, the board agonized over how to chart a new course for the company.

Yang and Yahoo’s era had clearly passed, and the longer he remained involved, the harder it would be for the company to make a dramatic break from its past and move forward. If recently hired CEO Scott Thompson is to have any hope of moving the company forward, he needs a clean slate. More importantly, employees and shareholders need to have faith that he is in charge of strategy and decision making.

That means that while Yang was the first to leave the board, he hopefully won’t be the last. There were already rumors swirling Tuesday that there would be more departures from the board. Let’s hope that’s true. This has been one of the worst boards in Silicon Valley. And chair Roy Bostock, one of the board’s longest serving vets, who has overseen the hiring of three CEOs, needs to be the next to head for the exits.

Other long-time members should also probably step down, including Gary Wilson, a general partner at, Manhattan Pacific Partners (2001); and Arthur Kern, an investor and former radio executive (1996). This would give Yahoo an opportunity to bring in four fresh, dynamic voices who could help Thompson envision a way forward for a company that still has so many tantalizing assets and remains one of the most visited sites on the Web.

Yahoo has attempted to reboot several times over the past decade and stumbled each time. Just because the company keeps getting another chance, doesn’t mean it will continue to do so. This could well be the last chance the company has to seize the future and restore itself to glory.

It’s an opportunity that it can’t afford to waste by holding on to anything — or anyone — from its past.