Everybody's right on this one (at least partly right).
The economy is a factor. It makes for a more Darwinian environment. The bar for survival is raised. Errors in judgement get the ultimate penalty. In a better economy, a newcomer might have more time to get its footing. A long-standing favorite might be forgiven if it stumbles and have a better chance of coming back.
The restaurant business ruthless. It has the highest failure rate of any business (even in good times). Those newspaper quotes make it sound like some people don't know that (or forgot it).
A restaurant is not a means of personal self-expression. Seems like a lot of people don't know that either. They open their dream is to open their personal "dream restaurant," apparently to please themselves.
McDonald's excels because they are consistent and because they excel at finding good locations. It really is location, location, location.
A new restaurant has to be tried. There are a lot of restaurants near me. I know they are there. I've gone by them. I've even heard good things. Somehow I've never bothered to go in. Introductory offers often only draw committed bargain hunters. The trick is to create some kind of buzz.
Neighborhood restaurants need repeat business. Getting local people to keep coming back is the tough part. There are some restaurants in my area that I tried and liked but somehow it doesn't become a place I go to regularly or even occasionally. A restaurant needs to build a core of regular customers to sustain it through economic ups and downs.