I don’t think unrating a contest makes the experience better for anyone. It just makes the overall contest fair, because if there is a good enough ratio of contestants who suffered, or even a majority who could not see their verdicts for so long, it just does not make sense for the contest to be rated.
Because the queue issues started at 11:15pm, and piled on to the very end of the contest. When the contest ended, the submissions from 11:30 hadn’t been judged for quite a few problems/users - thus we had to make it unrated at the very end, sorry :((
The detailed description of the decision is here for anyone interested.