Yes, I can prepare my own lunch. But it takes about 24 hours to make a vat of delicious homemade ramen that will feed 500 people. Do you know how long it takes to make a single serving of that same ramen? ...About 24 hours.

Likewise, an office with 100 people can easily have a whole variety of fresh fruit and produce to spontaneously choose and snack from and most will get eaten before any goes to waste. When I buy produce, I have to get exactly what I'm going to eat which means my weekly trip locks me into exactly one set of produce that I'm stuck with.

The set of foods that scale down efficiently is a very small subset of the set of foods that I like to eat.

Also, pragmatically, the free food was a perk of the job that I factored into the compensation package when I took the job. Losing access to the free food is effectively the same as taking a pay cut or giving up a couple of vacation days. Given the state of the economy, I think this is actually a reasonable way for the business to save money right now, and I'm much rather give up lunches than see layoffs happen, but the compensation package has shrunk.

Also, there is real value in not having to come up with new food to eat.