Not sure about that harming the relationship. Honest opinion sharing is a good thing. When a trusted engineer friend of yours tells you of shortcomings in your product, you listen. Maybe you missed something, or just disagree, but you can use this input to improve your product. Maybe its a design thing, or a culture of development, but identifying the shortcoming is step one. There are things that Apple can do long term in response, and sticking their fingers in their ears and ignoring Woz is one of the least productive.