This is something that, I hate to say, will probably take a law to fix. Companies in general have shown a resistance to understanding why this is a problem (even when well intentioned).
This. As long as consumers have no way of knowing whether or not their information is being transmitted, what information it is, and how it will be used, corporations will continue to do it at will. We need strong user data protection laws here in the United States that make it extremely clear what rights you are signing away any time you allow a service to collect personal data about you.
Its bigger than that. We are at a point where I would pay a monthly premium in order to keep my privacy and would rather have a bunch of free tiered alternatives that are all explicitly non-private. Because lets be honest with ourselves nobody but us really gives a shit about their privacy. And it is a billion dollar industry. Let people who do not care keep the free shit at an up front cost rather than all this running around corporations do now. Or I can even see a future where the government gives you free internet in return for data mining 100% of it.
Actually, even if you're paying, the service operator may be mining your data. This is the case for example with cell phone operators: you pay a monthly fee, and yet they use your geolocation to send you custom advertising, sell market studies, etc.
Not parent, but I too am paying for email for years and am very happy with FastMail. You can see a lot of work is going into it lately now that they're independent again. Can't recommend them enough.