That would be my guess, too, assuming that customers can't otherwise tell the difference between real non-Starbucks stores and the fake non-Starbucks stores. A Consumer Reports taste test in 2007 placed Starbucks's coffee behind McDonald's, with a mixed followup review in 2009:
http://www.consumerreports.org/cro/food/beverages/coffee-tea...
http://www.consumerreports.org/cro/magazine-archive/august-2...
Starbucks had consistently above average coffee at all of their stores at a time when it was hard to get above average coffee consistently. Since then, a number of places have offered good coffee - McDonalds isn't prestigious at all, but they now serve Newman's Own which is quite good. Subway serves Seattle's Best, so during busy times when the coffee isn't old and burnt, that's good. Heck, 7-11 has pretty good coffee these days. I prefer all three of those to Starbucks for plain coffee. Starbucks does make a good Americano though, and I don't drink the fancy mixed coffee drinks so much, but my fancy coffee drinking friends say Starbucks does it pretty well.
These days, it's not hard to get a cup of pretty good black coffee in a lot of different stores in the USA. Still, Starbucks is usually playing the Beatles or classical music, has a comfortable enough ambiance, and employees who are pretty happy and friendly. So I'll grab a cup of joe to run from Subway or McDonalds or 7-11, but if I'm going to sit down and read a book, I'll lean towards Starbucks. That's what they've got these days - their regular ol' coffee isn't anything special.
I'm a little perplexed by the report that the 15th Ave Coffee and Tea is doing so poorly since their store is constantly packed with people. The only thing I can imagine is that your typical Starbucks does the lion's share of its business on the strength of 'to go' orders, which the new Cryptobucks locations are expressly designed to minimize.
The coffee at the new places is definitely better than your average Starbucks, in any case. It's also better than a fair number of independent coffee shops in the same vicinity.
Hamburgers and french fries are a good example of where this is a good quality to have, more so than most food. Coffee is less so, especially for coffee snobs, but for people who need their morning fix all that's required is caffinated liquid marginally below your gag reflex threshold, which starbucks can usually manage. But, however just because standardization works for the _coffee_ part of a coffee shop, it doesn't work for the _shop_ part of it. The idea of a "coffee shop" is much much larger than a shop that vends coffee, and that bohemian ideal is not so amenable to industrialized standardization in the same manner as burger patties.
On the other hand, if the non-branded stores aren't succeeding either, maybe the coffee's just bad.