So you are a teacher right? Well maybe you should learn that sterotypes are wrong and hurtful to young adults. Please give some credit to the waiters and waitresses that work and contribute to the economy, instead of simply draining money from their parent or student loans.
If you get good service from a student aged server or waiter, please leave a tip. You don't need to leave 20% or anything, but realize that they split it with the hostess, busboys etc. I haev never worked in the food service industry, but I know from friends that customers like you that are total pricks are why they give you such bad service to begin with.
Final thought- you make way more money than the waitresses and servers- so remember $5 to you is a tip, to them its an hour of work. Just remember that the next time you go into Applebees and bitch about fruit.