National chains like Whole Foods (and Costco, and TJ's which is sadly becoming a nat'l chain) often have a base of products and then a whole lot that are different depending on which location. In CA where trends have a tendency to start or bloom quickly, other stores will compete quickly for the 'healthy' buyer. This may also be true in places like Austin, NYC, Charlotte, etc. In cities where drinking on public streets and partying 'til you puke is the major draw, they are very different. And I guess they should be since they don't really exist to please me, but to please the general populace and generate profit.
Where I think WFoods isn't too big too fail, but is positioned for a big fall is when public awareness becomes such that even the most snooty buyer figures out that WFoods is 80% hype and 20% decent. There has already been one mini scandal of some group filming the employees exclaiming that of course WFoods doesn't carry GMOs while the CEO admitted that you can't have a major grocery store free of GMOs. They've positioned themselves above the fray, and when average folks figure out they aren't, they will see a reduction in customers and stock prices. We all accept that Albertson's, Kroger, etc. are stores where we have to scour the shelves to find healthy; when public awareness is such that most people realize that about WFoods, there will be a loud thud as it falls on its collective ass.
I think of WFoods like the woman who wears wearing a padded bra. A lot of guys won't care, but the guys who wanted to see big yabboes when the blouse came off will. WFoods won't go down the tubes, but when its thin veneer of "healthy" comes off, it will suffer from losing those who shopped there for the snooty, or healthy factor.
And still, I like their cheese section.