A bit further down in that same interview, Adm. Venlet said:
The required changes to the aircraft aren't a matter of safety or of the F-35's ability to perform its missions, Venlet said. They're necessary, though, to make sure the plane's structural parts last the 8,000 hours of service life required. Nor are the weaknesses surprising in the world of fighter jets, he added. The discoveries are "not a quote 'problem with the airplane,'" Venlet said. "It's a fighter made out of metal and composites. You always find some hot spots and cracks and you have to go make fixes. That's normal. This airplane was maybe thought to be a little bit better, wouldn't have so much discovery. Well, no. It's more like standard fighters."
Not as sensationalistic and useful to the "F-35 is worthless and needs to be canceled" crowd, but very important for us all to remember.
These aren't reasons to cancel the aircraft, but rather reasons to move back towards separating prototypes and developmental models from production models.
A bit more delay in IOC in order to "get it right the first time".