As usual on a techie forum like WW, you folks are speaking from a technical perspective. Most techies not only understand how email works, but learned a long time ago that free email systems have big tradeoffs.
IMO, the average user is just now (during the past 8-15 years) realizing the security and privacy conditions present when using websites, emails, etc. I believe the average user, for many years, thought of computers/email/websites like any other device in their home. They were never concerned about privacy when they put a cake into the oven, or while turning on light switches. And they certainly did not worry about their televisions spying on them.
But most also did not understand how the Internet worked, or the footprint that each computer/email address generated.
I think many are just now realizing that the Internet doesn't work like a microwave oven where no one (unless they are sitting in your kitchen) knows about food you just heated. And when you tell them Google is reading their emails, it feels like a set of eyeballs peering back at them during their favorite late night show.