Over the last 10 years I've been a big consumer of Google services. First it was Gmail, then Google Voice, Calendar, Currents, Latitude, Keep, etc.. I very quickly became invested in the Google ecosystem. However, I've always been sensitive about my privacy which made me a bit nervous about paying for these services with my private information, particularly my browsing/search habits. You won't find me on many social networking sites and when you do the details you find will be very vague.
So when Google started forcing Google+ on people I became even more dismayed. I tolerated it at first and then to use my favorite apps like Latitude registering for G+ was required to use and then reviews in Play required G+ membership. And then came the new tabs in Gmail, notably the "promotions" tab. Great, forced SPAM that I can't opt out of and still get the value of this new feature. So these events spelled the beginning of the end for Google in my life. Combined with my sacrificed privacy really started the search for alternate services.