He's right in that some sites should be 'social' and some shouldn't...

But for the life of me, I can't think of any sites that shouldn't be and are. That portfolio site that he says shouldn't be, isn't, and that's correct. It's not to talk about the art, it's to display it. The site correctly knows it's niche and it's acting appropriately.

However, if that site had been DeviantArt and tried to avoid having 'social' features, it would be devastatingly wrong.