I am very surprised by the low rating. If I have to guess the reason, it is probably the fact that the occurrences in the series cannot happen in real life. The plot involves time travelling, but not as in sci-fi movie, but in a poetic way, not trying to explain it somehow, because it does not matter.
If this kind of thing doesn't bother you, you should definitely try this series, as well as the excellent Israeli film Jellyfish, which was also created by Etgar Keret and Shira Geffen.