It's About Flair, Not Flavor
The secret of a good catered event is in the presentation, not the food itself. For instance, acorn-fed jamón Iberico is the best of the best when you're looking for cured ham, but unless the catered event is a food critic and sommelier's convention, no one will probably notice if a regular prosciutto gets swapped in. The same goes for the rest of the food -- cooking high-volume is an industrial process where the love and art shows through in the presentation, not the flavor. Often the caterer's job is to make the food look so good that it doesn't matter what it tastes like.