They're happy because they're rich.
I love Whole Foods, but just on principle, I refuse to spend THAT much on produce when I can get both organic and non-organic cheaper at Trader Joe, and even cheaper at farmers' market near my house every Monday.
Their house brand 365 is fantastic and very cheap. Their house wine at $3.80 is their version of TJ's two buck chuck and really good.
Mostly, I buy their condiments, 365 items, or specialty items like exotic cheeses or desserts if I'm bringing food to a party. And their bulk items like oats, brown rice, lentils, etc I stock up on every few months because their price per lb is very good and TJ's doesn't have a bulk section.
I cannot for the life of me go into a regular grocery store unless I'm getting water or paper towels. The produce tastes horrible and I can't stand being in a brightly lit circus with screaming kids.