There are plenty who claim that quirky and impressive office perks are pointless, counterproductive, or the wrong way to motivate people. Be that as it may, many startups—especially in tech—have baked those perks into their work cultures. But if history or probability are any guide, they may not be sustainable for the long haul. You may not think so, but putting your unlimited cereal bar on indefinite hiatus can actually do more damage to your culture than you might think.