Google Now has done the same for me, told me how long it will take to get to a bar I frequent. My reaction was quite exactly "Oh that's neat, thanks!" and I went and had a great burger that night. Totally OK for me Google. I respect that people have different privacy thresholds, but I think the fact that it's different for everyone is being lost in articles like this.
One tiny caveat being that, Google (and others as well, to be fair) will be able to indirectly collect data even on the privacy-aware part of the population who don't use Google much. The simplest example being, even if you don't use GMail, still some part of your emails inevitably end up in GMail inboxes. Now also consider this: just being a guest in a Google-stuffed house means you are under surveillance. So no, it…
Going further, given that an encrypted email to Gmail will simply be unencrypted and then available to GMail, include in the protocol authorized (via both white and black list means) agents of the recipient. So, if you are hosting your own email but the intended recipient is expected to be not hosting their own email, the sender can blacklist "agents" such as Gmail and Yahoo! Mail, or blacklist all except for those chosen to be white-listed such as Proton Mail.