Field trips are generally the only time my kids get lunchables. Usually for field trips, our teachers request the kids bring completely disposable lunches, so they don't need to carry a lunch box all afternoon. Lunchables are a simple way to accomplish this.
However, that being said, as a special education aide, I am consistently appalled at the lunches some children bring. An adhd kid doesn't need a 1/2 dozen cookies, hostess cake and a Pepsi in his lunch, thanks.

Likewise, the child who can't stay awake needs more than a mayo sandwich and water.
(*Just a note I addressed the mayo sandwich child as I thought it maybe a monetary issue in the home, turns out the child goes in spurts of what he will eat and refuses to eat anything else. About 3 weeks later he was on white milk and pb&j. I had the social worker and principal discuss with the parent too, because I couldn't stand the thought of the child consuming this each day.)