Why Okitsura anime rating is so low ?

Some people have already hit on it, but I’d say just as weebs and many others are drawn to Japan—often due to its seemingly exotic, otherworldly culture compared to the west & western media, many Japanese are interested in Okinawa/Hawaii/etc, and this particular anime, because they find Okinawan/Island culture to be interesting and refreshing.

However for many weebs, they already have a distinct interest in another foreign culture (Japan) and so learning more about Okinawa is not particularly associated with their general interest in Japanese culture. So in this way, the show is definitely more catered towards Okinawans and Japanese viewers curious about other cultures, rather than people curious about mainstream Japanese culture.

And this show doesn’t just use the island as a backdrop to a loosely related plot. In fact, Okinawan culture is the core of the plot, alongside the character dynamics which are driven by their experience of Okinawan culture… Imagine if summertime rendering wasn’t about a thriller mystery, and instead was about to Wakayama Prefecture, it might have been more niche.

Likewise, the Hokkaido anime was focused on life in Hokkaido, but also had waifus and major fan service in a way this show doesn’t.

So if you’re not really interested in learning more about Okinawa, then you probably don’t rate this show/find it boring.