That's what the autopilot is for! And yes, in other lines of work, you must bring your own lunch or buy it at work. The difference is, of course, that almost all other lines of work give you a lunch break. It's not the time that's the most important part (we generally have adequate time in the cruise), it's the opportunity to wander off and go and get something to eat of your choosing if you didn't make your own. We can't do that.
Therefore, I don't expect airlines to provide us with free food. BUT, they must then provide several 'menu' options, and preferably at a reduced price, since we do have the ability to shop around (essentially they would otherwise be abusing a 'captive' market, their own employees!)