Google didn't create the switch to mobile, they are years late to the party. Apple initiated the mobile smartphone revolution. Now billions of people are coming online, many of whom never ever had a desktop with internet, especially in developing companies.
This is a disruptive change, and it is undeniable reality. Even if Google didn't change the mobile search ranking, eventually non-mobile ready sites would lose traffic from frustrated users picking alternatives that are mobile optimized. What would happen is, mobile users would say "man, Google Search sucks, every time I search for a site, it gives these horrible, slow to load, hard to use sites on my phone" At some point, a competitor, possibly even Apple, would release a mobile-ranked search engine.
Maybe they'll be a button to get the desktop results even on mobile, or maybe "Request Desktop Site" in the mobile browser will give you Google Desktop search. But to blame Google because you're going to eventually be forced to update your site is just laziness.
It's not Google who brought this on, it's your customers. They've changed their access patterns, and if you want your business to thrive, to you need to follow your customers. Sometimes that even means native apps in app stores.
I'd say this is a good wakeup call and really, Google took way too long to seriously target the mobile Web. Chrome only recently got Add to Home Screen and Push Notifications, two of the biggest things missing. We're now 8 years post iPhone (2007). The fact that Search ranking is just now, almost a decade later, targeting mobile friendly means Google was seriously lagging the usage patterns of most of the world.