Board Thread:The Quarters - Q & A/@comment-4541818-20171218115911/@comment-25085701-20171219231602

The original reason for this was that if you had a lot of Dailies and were on a boss fight, it was very easy to get overwhelmed by damage if you were struggling to consistently complete your dailies, and even more so if you didn't log in every day, as your dailies would do incremental damage based on how many days you skipped.

This was an across the board 'help me reset my dailies' skillset. It is somewhat less useful now that you only ever take one day's worth of damage even if you haven't logged in for a week.