...Just try explaining to your kid why there are three tables around you with people just sitting there and she has to eat while sitting on the ground. If the tables are full of people eating food it is easier to understand but waiting for food? not the same at all...
I agree it's rude to watch someone struggle and not offer help, helping is called being courteous. Things like lend a helping hand, or a seat on the bus, etc..
But with regards to tables at CS. I just totally disagree (can we agree to disagree?). There are no posted rules about seating in the public areas. There are no signs stating you can only be seated if you have food in hand, that's just ridiculous. Are people allowed to use the restrooms at CS locations if they are not eating there? Or grab napkins from the condiments counter to clean a mess even though they didn't buy food? Furthermore, if someone is saving a seat for the one ordering food for their party, they are using it as a patron of that restaurant and most definitely are entitled. Why is your right to sit any more important than their right to sit down. All parties have equal right to public seating.
The exception would be ADA seating, that most definitely is for people needing ADA accessibility and is marked as such. You and everyone else have just as much right to have a member of the party grab a seat while someone orders. If you choose not to, then that is your choice.
Personally I don't even think using a table at a CS and not ordering food is inappropriate. If so, then I suppose sitting on a park bench in Tomorrow Land at Magic Kingdom but eating a hot dog from Casey's is inappropriate? Afterall, it is not a bench dedicated to Casey's and therefore should be only for guests of Tommorrowland...I could be wrong, but Disney does not restrict public seating to patrons with food in hand. There are no rules saying "if it's crowded, give up your seat for people with food in hand"
As far as explaining to my kid that all the tables are full? It's just that, the tables are all full and that's life. We find another spot to sit as nearby as possible and enjoy the atmosphere and scenery there. But then again we must be breaking rules because shouldn't we be eating at the place we bought our food otherwise we are taking a seat from someone else?
Then again, maybe it's me. I don't let line jumpers bother me. It's just not worth it to me. It is such a small segment of the guests who do it that it's not worth raising my blood pressure over when the fact is, an extra person or two cutting me isn't really going to impact my wait time that much. Why should i let it impact my enjoyment?