But when The Village was zoned, it was explicitly done with street-level retail for a wide variety of restaurants. There are over a dozen restaurants within a 5-minute walk of Facebook's offices, plus a Walmart, Safeway, Whole Foods, and produce market, all of which have ready-to-eat meals.
Something that's left out of a lot of the news coverage of this: it's not a law but a development condition attached to the particular property that Facebook is occupying. When a real-estate developer wants to develop a piece of property, there's a complex negotiation with the local municipality (or county, if it's in unincorporated land) that includes things like contracting for water/sewer/garbage services, how to ensure there's adequate police & fire coverage, how the town will build new roads to handle traffic generated from the property, what's the impact on schools & community services, and what types of dwellings & permitted uses are available for the property (you can't build a skyscraper in the path of SJC airport, for example, nor can you build a chip fab on residential land). Written into that contract is the cafeteria clause under discussion here. While I have some doubts about whether this is a good thing (I've got another comment here where I expressed mixed feelings), it's a contract and not a law, and obviously Facebook has felt that the restriction is not too onerous for the building to be worth occupying.