It's not about toughening up at all. I have three boys, all three have differing tastes and likes and we've raised them all the same way. It isn't about catering to their whims, its about figuring out what works for each one individually. Sometimes that means trade-off and choosing battles.
Just out of curiosity, what would you consider an appropriate, healthy lunch for a 5 y/o?
Turkey and cheese roll-ups, an apple and a few whole-wheat crackers? 5 y/o's are easy. They eat what you give them or they go hungry. They'll figure it out. It's 8 and older that get tougher because they're much more opinionated and aware of all the other sh!tty/tasty foods around them. Either way the lunch needs a decent amount of protein, way less carbs, esp since no matter how active the kid is...those are all a bunch of refined carbs. And please don't think the peanut butter on pre-packaged PB crackers is protein. That discussion belongs in a different thread entirely.
Peler's right. Try and find some fine print somewhere about them finding your kid hungry, they have the rigth to charge you. Either way I can't understand taking away a bunch of different crackers and snacks and replacing it with a frikkin corndog