Google is getting smart by changing algorithms consistently. Last year itself there are many small minor algorithm refreshes and few major updates. Thus, it is understandable that google trying to get rid of many ordinary sites and trying to showcase only good authentic sites.
But, There always seems to be problem with the updates as it is not work as expected by google. For ex: after some latest updates, few good sites are also got hit in the line. So, seo becomes more and more interesting and lot of research is needed to make things done to reach where the money is, that is google first page.