Firstly, thanks for reading the ToS and for raising your concern. Not that it means much, but our goal is not to screw over our users. This is the first time someone has raised an issue with the ToS.
We understand how personal user fitness data is, which is why we’ve tried our best to leave data in the control of the users. A first step was to make sure that users actually see the ToS, and we require all users to scroll through them and accept before they link any data with us. But honestly, we know the ToS is daunting for many users, which is why we give clear switches for users to revoke our access to using their data (both for model training and for using their anonymized stats in aggregated statistics); we respect the user’s decision to revoke our access in these ways, even though our ToS doesn’t require us to. Your fitness data gets immediately deleted when you delete your account; we also allow specific sources (e.g., Garmin) to get deleted without deleting your entire account.
But we agree with you–the ToS are too aggressive. For context, we had them drafted by a well-respected firm in the Bay Area. As a startup, we didn’t have the budget to carefully, line-by-line, draft terms that perfectly fit our site. Instead, we gave the firm some ToS from large companies like Strava and Garmin, and asked them if they can draft something similar. We wanted to ensure that we were legally allowed to glean insights from the fitness data of our users, and when we read the terms, it looked like it provided that, which is why we approved it. We aren’t lawyers, so we didn’t understand the ramifications of the legalese, and we’ll make sure to emphasize that we respect the user’s decision to remove our access when we re-draft them. We’ll shop around again for other firms that specialize in this area.