It's entirely fair when it's in response to a claim like this: "It looks like something I did in high school, in one weekend."
Personally, I think the site is fine except that I'm getting some pixelation on some of the images (especially the main one, which is scaled to match the screen size). But then, I work for Microsoft.
Oh, I do too. The site is fine, you're right. But for a company with the amount of resources yours has, and for a product launch as important as this is, fine is not good enough. It needs to be exemplary. This isn't—it's just OK.
It would be a lot more reasonable to ask him to show competitors within a similar industry who have produced a better launch site.