Google's search result pages don't rank high either. I agree that it is a negative, but I do not see the double standard.
To equate Google.com with a scraper site that scrapes StackOverflow and tries to outrank the original by changing publishing date and other nasty tricks is not too sane. There is no double standard and there is no fair comparison.
It is not Matt Cutts who preaches how bad it is; it is the users (you and me) who are complaining about this and asking Google to take action. It is the user metrics showing something is wrong with the quality or experience.
Finally it is about intent. The spirit of the guidelines. It is only when blackhat spammers start exploiting techniques, that those techniques become punishable offences or are taken away. Google gives us popular search keywords? Spammers will automatically create crappy pages to target those. You can get a site to link to you by writing a quality article for their visitors? Spammers will write or outsource crappy articles and ruin article marketing for everyone. You are a charity and you want to create a widget with a link back to your site? Bummer... better add nofollow, because spammers used baity widgets like "Which zombie am I?" to link back to their clients' websites with targeted unrelated keywords.
If you go to the Google search results do you think: Damn what a commercial site! Animated ads everywhere! And all these scraped results they are trying to rank for without giving credit to the content creators...?
"Ads above the fold" are usually Google's own advertisements. They ding webmasters for forcing their own ads onto their readers. So it is a decision about quality and reputation, not money or bullying small sites.
Do the all-things-being-equal test. Two sites equal in all regards, yet one has animated advertisements above the fold. Which one would satisfy your users the most? It's a tiny factor, but it is there. And it is there for a good, not a nefarious, reason.
Ironically, what Google could be summed up as is a scraper website absolutely FULL of ads above the fold ( http://searchengineland.com/figz/wp-content/seloads/2012/01/... ). If you place ads like Google does, your website won't rank shit.