You obviously haven't ever been in the restaurant business. Granted, there are those who could care less about their customers, but waiting tables (especially on busier weekend nights) is one of the most taxing, stressful things one can do. It's not as easy as "delivering food to the table"
I', sorry but I disagree a little. There are some servers who will go out of their way to make sure that your meal is an enjoyable one. There are some who just deliver the meal only to be seen again delivering the bill. There are some who just take the order while someone from the kitchen delivers it (this happened to me Friday night). The first server would get the tip. The 2nd and 3rd would get none. Like the poster said, it is something earned. When these folks are hired they are aware of the wages that they will be paid by their employer. If they want more from the public than they had better make sure that they are at tip top in terms of service. And yes, I can state this as a qualified opinion as I STILL wait tables occasionally for a friend in his restaurant.