What's the point? Do we really need to eat before we eat?
Along that logic, what's the point of a dessert (or soup course)?
Guess it really depends on the main course size. We've pretty much stopped eating out most full-service meals (as well as some fast-food places such as Five Guys and Hardees) because portion sizes have typically become fit only for the obese. Carrying home left-overs has no interest for us. Along that line, I do find it odd that people will order appetizers and/or dessert but eat only about 1/4 - 1/2 of their entree.
It may also depend on whether the dining is to be a relatively quick meal (typical American chain restaurants where management drives for maximum table turnover) vs. more social, European style dining which tends to be more centered around an evening out through a series of smaller portion courses (single table usage).
Another use for an appetizer might be to keep one occupied while the main course is being prepared. In the US, the salad course tends to serve that purpose, but in other countries, the salad course (much smaller portion size than a typical US portion) is typically served after the main course, prior to the cheese, nuts and/or dessert.
I'm guessing you also find it odd that Italian cuisines often have a pasta course before the main course.
<message edited by mjambro on Thu, 09/6/12 6:23 AM>