I love this show. A superhero show more focused on aliens and tech but with enough drama to make a great story. So, kinda weird but I feel like it really works. The characters are interesting and they did a great job with keeping true to much of them while updating, rather cleverly, what was needed to make it a bit more modern.
I love that Superman/Kal-El has almost nothing to do with it too. It is a really neat look at a world I always wanted to know more about. I love the cinematography too. Admittedly, it took a few-ish episodes to get me really sucked in but when it did, wow! I hope they keep it going long enough to reach a conclusion.
No idea why it does not have better ratings but I find critics are horrible at rating things and I do not listen to any of them. The public is generally better but it often rates things just low enough that I would not watch it if I had listened to them and I would have missed something great (and vice versa.)
Who cares about rotten tomatoes. While I usually like them, Metacritic I totally disagree with at 50-something%; that seems totally off. IMDB at 70% is better and I could see that as closer to what I would expect but personally I would rate it way higher.
Give this a chance and decide for yourself but try to keep an open mind as it may be a bit different from what you expect in places.