"The core creative community is very small but is also very close – there’s been changes there, but the change isn’t perhaps as dramatic as you might assume."
He's saying that there have been changes to their design process and the structure of their design organization, but they haven't been as dramatic as people might assume. Meaning: iOS 7 is a dramatic change from iOS 6, so one might assume that there has been a dramatic change in who's designing the user interface and how it's being designed, but that's not the case.
Regarding the critiques of iOS 7/8 design, keep in mind that it's version one of a new design language. Look at Aqua in the Mac OS X Public Beta a decade and a half ago, and compare it to Aqua in Mavericks. It's going to take some refinement. But from what we've seen in Yosemite, and to a lesser extent iOS 8, they've already begun the process of refining their new design language.
"It’s a great time to be an iOS developer." Marco Arment, June 6, 2014
The Verge wrote: "iOS 7 isn't harder to use, just less obvious. That's a momentous change: iOS used to be so obvious." In iOS 7 basic usability features such as making buttons look like buttons are now stuffed under Accessibility options. About this, Tumblr co-founder Marco Arment wrote: "If iOS 8 can’t remove any of these options, it's a design failure." (And iOS 8 hasn't.) Michael Heilemann, Interface Director at Squarespace wrote, "when I look at [iOS 7 beta] I see anti-patterns and basic mistakes that should have been caught on the whiteboard before anyone even began thinking about coding it." And famed blogger John Gruber said this about iOS 7: "my guess is that [Steve Jobs] would not have supported this direction." Enough said.