Currently to schedule email delivery of saved views, you must be:
The creator of the report AND
A user with at least owner or contributor permissions.
The #2 condition is because a report's settings could allow for sharing views as a webpage instead of an Aha! link, and facilitating external viewing is intentionally restricted to owners and contributors.
That said, there are cases where an individual Reviewer user wants to set up an email schedule subscription to a report (and does not need to share it more widely than that), but is currently not able to do so.