From a long-time scout leader:
The leader can never please everyone. One family complains, "we can barely afford this trip as it is -- we can't add in meals too. Let us bring BP&Js.". Another family declares that hot dog stands are absolutely not sanitary -- it has to be a sit-down meal, and the girls need a rest mid-day anyway. Another family says that the whole trip is a bad idea, and they should've planned a trip to a water park. Another family readily agrees to hotdogs, but then once they're actually on the trip, they want to change to a sit-down venue.
The leaders have made the decision for a reason. Maybe it's that they've planned a stop at a park for lunch. Maybe it was economic. Having been through it LOTS of times myself, I can tell you that having a group of kids buy food is a LONG and DIFFICULT process for the leader. Yes, it's easy to think, just get them all the same thing . . . But then you get into, " this isn't the kind of hot dog my mom makes, why is this apple green?, i wanted a peanut butter cookie instead of chocolate chip. An amazing percentage of them are not adept at saying what they want, finding their money, putting their money away. Regardless, the decision is the leader's choice to make. If you don't want to co-lead, follow directions and pack the lunch.
Things to pack: Lunchables, a cored apple full of peanut butter and raisins, trail mix, cheese cubes, GoGurts, juice boxes . . . Things kids pack for any other lunch.