Risa

This makes sense.

All they care about is the general well-being of the temporal federation. Perhaps it's so difficult and wiggly wobbly that it's worthwhile letting one of your temporal agents languish in the 1900s for decades if in the end it works out for the timeline. Especially if strange circumstances somehow strengthen their position in the temporal wars.

Or the borg achieving time travel tech was an inevitability and Janeway destroying them was a necessity to keep the borg from assimilating all life in a manner similar to First Contact (thus negating the existence of the temporal police).