Artificial corals are easier care and less expensive. If you are like me, most of the people around you don't know about reefs and they would like both artificial and real coral. Just don't put both in the same tank or else people can see how fake the artificial stuff really is.
I think the main factor is the added time commitment for owning a beautiful live reef. Real corals will need Mg, Ca, pH, kH monitored weekly, cleaner water, good lighting, fish compatibility, and perhaps a few other things that I cannot think of at this time. Also many reefers experience some type of algae problem.