Like most chain restaurants they're for the lazy who can't be bothered to spend two minutes on the internet looking up a decent local place with real food. Chain restaurants tend to serve garbage that's engineered to taste OK-ish having been prepared somewhere miles off site.

Fast food places have something of a purpose, they fill me up if I'm short on time but with chain restaurants I really fail to see the point. The local establishments rarely cost more than the Applebee's and Chili's of this world (someone's got to pay for those vomit inducing Oliver Garden commercials and corporate overheads!) and the food at least usually tastes fresh. Sure local places aren't always a slam dunk and some food (often appetizers) might be bought in but the mains are decent.