I've had 2 of my sites slapped cold, both were on the first page for several competitive keywords, and I mean like 1m+ exact competition. Both sites had only original content! 500 word articles with images and videos posted daily by dedicated writers.
Guess what? Both sites had no linkbuilding aside from xrumer blasts. All my other sites are fine, only 2 out of 50 got slapped and only the two that had no links at all aside from direct spam. Many of my other sites have direct profile and blog comment links, but not only those, it's a healthy mix of other stuff, from social media, to videos to articles, bookmarks high pr blogs etc. I'm sure they will come back after a few months of linkvana link building but it still sucks.
The lesson I got from this is that if you only have shit links to your site then it doesnt matter how good your content is, youre gonna be slapped. But if you have a large diversity of backlinks, your seo will only grow stronger. Think about it, if you could do an xrumer blast to your competitors site and get them deindexed that would be a deadly tool. Big G isn't stupid which is why they cant devalue shit links, but they can punish you if it is blatantly obvious that that's all you do for seo.