The only reasonable explanation for me after years of slipping down the slope, and trying to rationalize and defend Google's actions such as :

0. Reading through all our email (We were so naive back then)

1. Google saying it would never link data from its other websites (Youtube, bloggr) with our Gmail id, and then going ahead and doing just that

2. Google announcing Android as Free, Open-source Operating System, then with each update removing functionality to Google Play Services,

3. Google sabotaging the permissions system, by clubbing innocuous, essential permissions with down-right dangerous/malicious ones

4. Creating amazing tech that could provide a quantum leap in the quality of life (for the first world at least) but will further enable Google's all-seeing eye to impinge over our daily life (Self-driving cars, Google Glass)

5. Acquiring home automation companies, robotics company with large defense contracts,

... is that Google is well on its way to becoming truly Evil.

People say that the NSA's unsaid motto is 'to collect it all'. I say that motto sum's up perfectly Google's vision.