What makes you say they haven't? There have been many stories of search algorithm changes hurting businesses http://www.smeinsider.com/2015/06/23/google-is-rui

What makes you say they haven't? There have been many stories of search algorithm changes hurting businesses http://www.smeinsider.com/2015/06/23/google-is-ruining-small-businesses-with-algorithm-change/ http://www.smeinsider.com/2015/06/23/google-is-ruining-small... for one