Why not? There are plenty of CEOs in their 70s:<p><a href="http:&#x2F;&#x2F;www.theatlantic.com&#x2F;business&#x2F;archive&#x2F;2010&#x2F;06&#x2F;the-14-oldest-ceos-in-america-how-much-they-make&#x2F;58375&#x2F;#slide1" rel="nofollow">http:&#x2F;&#x2F;www.theatlantic.com&#x2F;business&#x2F;archive&#x2F;2010&#x2F;06&#x2F;the-14-o...</a><p>And there are a number of CEOs with multi-decade tenures:<p><a href="http:&#x2F;&#x2F;fortune.com&#x2F;2015&#x2F;05&#x2F;05&#x2F;14-longest-serving-ceos&#x2F;" rel="nofollow">http:&#x2F;&#x2F;fortune.com&#x2F;2015&#x2F;05&#x2F;05&#x2F;14-longest-serving-ceos&#x2F;</a><p>The Bell System had something like a 70-year monopoly, and it&#x27;s certainly possible that Facebook has staked out something equally enduring.