Ives has led the entire design process for Apple's device range, at least until the relatively recent past. Like you I'm not sure to what degree Apple's problems as a whole are attributable to him (certainly not everything of course), but as a designer of his calibre he should be able to make the design decisions that produce a better UX in the product, with or without Jobs. It's why he earns the big bucks.
With that in mind, I'd say the issues in Apple's recent range (of a design nature) can be attributed to him. He's taken minimalism past its extreme in recent years, getting rid of things that are part of the device's essential nature in favour of aesthetics and creating something that has great UI but terrible UX.
With that in mind, I'd say the issues in Apple's recent range (of a design nature) can be attributed to him. He's taken minimalism past its extreme in recent years, getting rid of things that are part of the device's essential nature in favour of aesthetics and creating something that has great UI but terrible UX.