> It is truly an awful contract, with no benefit at all to the employer that I can see.

The benefit is having an operating cafeteria (i.e. an amenity) for a guaranteed period with little or zero out-of-pocket expense other than providing the space. Unless there's obviously high-demand (coffee?), no catering company is going to commit to a long-term contract without ensuring some minimum volume to maintain staffing. Anything food related typically has ridiculously slim margins on average, especially when you count all the failed projects.

Catering is often an exception, but not this kind of daily staffed in-place catering. The most profitable kind of catering is where you can prepare food offset for discrete (though hopefully recurring) events across many (hopefully repeat) clients, and where you can quickly ramp up or ramp down staffing and facilities to minimize recurring costs.