-Stops people reporting the same player for the same offence.
-Allows people to comment to support or defend the report, explain what they were thinking etc.
-Allows people to see if there is a trend (player keeps on getting reported for trolling etc), so you can dodge.
That said, I would support reports after a period of time (6 months?) getting archived and becoming only visible for moderators, and the people involved in the reports. Still allows for accountability and if the people involved want to appeal they can screenshot etc. This gives the user more privacy, and allows people to move on from a bad past etc.

