Yahoo Chief Executive Marissa Mayer’s decision to ban telecommuting sparked outrage around the country, but left many in Silicon Valley wondering what the fuss was all about.

Working from home is common enough in the Valley, but that is in addition to – not instead of – the 40-plus hours spent working in the office. Despite the area’s image as a freewheeling space that makes much of the technology that allows people to work remotely, Bay Area workers tend to head into the office, especially at start-ups.

“Every idea we have is a result of more than two people sitting in a room, riffing on or trying to think up a clever solution to a certain problem,” said Sahil Lavingia, founder of payments startup Gumroad. “Things like that you can’t do over any Internet protocol.”

That does not mean Lavingia thinks his staff should never work from home. Just the opposite.

“Everyone should have a setup at home that makes them equally as productive, or close, as if they were in the office,” he says. “Many people put in hours before and after work, and on the weekends.”

The new policy at Yahoo, announced in a February 22 memo, calls for “all employees with work-from-home arrangements to work in Yahoo! offices.” The change goes into effect in June.

Many of the storied trappings of startup life – the free food, the game rooms, the flip-flops – are aimed at keeping people in the office. That goes for the engineers, often young and male, just as it does for other employees in groups such as marketing and sales.

And the private, Wi-Fi-equipped buses that shuttle employees from San Francisco to Google and Facebook and other companies based in Silicon Valley are meant to make the commute more productive, lest anyone advocate eliminating them altogether.

The lack of rules is also a hallmark of startup culture, and few companies will declare a firm policy on issues like telecommuting. But the message is pretty clear.

Apple Inc cofounder Steve Jobs liked to talk about the long hours employees put in at the company’s Cupertino, California, headquarters. “I’ve seen cars in the parking lot late at night, cots in some of the engineering offices,” he said at a 2010 press conference.