As a designer, I'm a bit confused by this criticism. The reason why I hate Facebook so much, is that because every single space is jam-packed with text and content. Negative space is important to give some visual space to breathe. I like the new design and google+ in general because it feels simple, clean, etc. Do you complain about google's search engine page being too simple as well? Maybe it's just subjective, but I like the empty space.