Really surprised at how many people here just think chain restaurant success is a failure of its customers. Totally ignores characteristics of a successful (and to a certain degree american) business model:
From a really good
blog post on why chain restaurants are so popular, here were the four reasons for their popularity (and this makes sense to me):
1) Predictability - All Baja Fresh have fresh same variety of salsa, just like all Starbucks (well most of them) make the same-taste coffee. When you walk into a Red Robin, you can expect perky waitresses (most of the time - well maybe not in Seattle). You can even expect bad food in some of them - no matter where you go.
2) Branding - Whether it's an upscale image (PF Chang) or children-friendliness (Red Robin), chain restaurants project an image and they do make an effort to ensure that what they deliver is consistent with the image. If you feel like a particular kind of experience, you simply have to select the chain and find the nearest one.
3) Convenience - For travelers in particular, you can usually find a familiar name in a decent size city when you don't have your Zagat review booklet handy and you notebook can't find a wifi hotspot that's free. Between a unknown local steakhouse with mostly empty parking lot and Outback, which one would you choose? Would you rather go to Big Joe's Tavern (you won't even find it on the web!) or Chili's for a big and juicy burger when you're out in Tennessee?
4) Sense of Security - No one, or very few people, enjoy looking like a freshman sitting in the registration hall. Most people simply like to sit down and feel like an old customer when they go out to eat - "Yes, I know your beer sampler is a great deal." When you sit down at a Friday's in Ukraine (yeah they do have one there!), you can expect them to have baby back ribs and at least one draft beer.
The last one is similar to what some folks have said here - but the idea that you want to be familiar with the menu or feel like you are "known" - sort of like Norm sitting down for a drink at Cheers - is a far more complex emotion set than just not wanting to try new things.
I live in west LA and enjoy having so many unique restaurants around - end up at one almost every night of the week for a work dinner. When I travel, my wife and I turn into foodies and search out the best meals we can find. But when have a reason to travel to the outer limits of LA, we are as likely to end up at a chain restaurant as a local place. To a certain degree we miss the chain experience in our usual dining experiences, and there are some amazing food creations out there (i.e. my wife loves the fried shrimp and cheezy rolls at Red Lobster, and who really can turn down a Pizookie at BJ's?).
Another example - I was just in Barcelona, with great dining experiences waiting for visitors around every block. The busiest place was the Hard Rock Cafe, and it was mostly filled with Europeans. Is it because all these Europeans are unenlightened? Or was it because they wanted an experience in addition to their food or they interpreted what Hard Rock offers as good value? Probably the latter. Or like us, were they ready for a good old fashioned burger or fajita after several days of desconstructed new wave expensive food - some of which was amazing, but a fair amount of it I would trade for a chain meal any day.