Thanks for sharing your thoughts
That may be my opinion only, but what you described is precisely what we wanted to avoid: people (meaning everyone) will go to the submission list, sort it by "popular" (thinking that these games are probably the most enjoyable), and play/rate a certain amount of them (probably not 50). At least that's probably what I would do, from an outside point of view. So the "top" games will get even more visibility/ratings. To quote you: "if someone rates a popular game they enjoyed, they'll be will to go explore and rate other games". Except that the next game in line would be the second most popular.
The same use case with "random" order would at least be more fair to games that are not on the top 50 (even if that's not perfect, I agree)
I'm not saying that having these kind of sorting is bad, but I would have activate it only once the ratings are closed.