So, if I go to McDonald's, I can't order myself a happy meal?
If you are not on a DP, ordering off the Kids Menu isn't ever an issue. The restaurants don't care, the servers don't care.
If you are on a DP, then it becomes a bit more complex because it IS about money. Kids will be forced to order off kids menus if under 10, but if over 10, they'll have a choice of either (I know because I just did this with my 10 year old who is now an "adult" on the DP...some places she ordered adult food, some places I ordered her appetizers for me while she got her entree off the kids menu.)
No one batted an eye at it.