A lot of the criticism for the new logo has been based on the idea that, "The new logo looks childish and unintelligent." While I agree that the new logo is definitely less academic looking than previous versions, I think it reflects the recent updates and changes Google has made to their overall brand. For example, this logo will make a lot more sense when paired with Google Hangouts. Yes, Google used to be a more "academic" brand, but they have changed a lot since they first started as a search engine.
Check out the video below to see their evolution: