Fetch wants to make sure that you get to use the rewards that you earned. While Fetch has not been compromised, we do find certain patterns where we want to make sure you are as protected as possible. This includes resetting your password.
We hear on the news about those large data breaches more often than we want. Malicious people are able to use the login information obtained to various apps and accounts, and take what doesn't belong to them. This is because a lot of people use the same login email and passwords across a variety of accounts.
Please make sure all your passwords are unique and you monitor any strange activity on all your accounts, including Fetch.