People with money seem to be on a binge to prove their status and flaunt their wealth by staging large, catered parties. As a matter of fact, in some circle of affluency, a party or social get-together isn't considered an event of any significance unless it's a catered affair.
With the same kind of reasoning, businesses of all sizes are using catered lunches, cocktail parties and dinner meetings to build their images and increase company sales. It's a matter of keeping up with the competition in promoting a company and/or product.
On a smaller, but just as busy marketing scale, more and more working mothers are paying to have catered birthday and graduation parties, as well as wedding receptions handled by caterers. The reasons are simple to understand--if she's working outside the home, today's mother just doesn't have the time or the energy to do all the planning and staging of a memorable party.