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.

I am watching both animes and I can say that "I got married to a girl I hate in my class" is superior in any way possible, its popular for some reason, the premiss is very unique and the characters are getting a big development in every single episode, in my opinion its the second best romcom of this season (behind honey lemon soda)

Is not an "inconsistency" when is intentional. You don't liking it doesn't make it bad either.

It's a unique and cute/comforting watch for me, and it makes learning about Okinawan culture fun. This is why (to me) you can't always trust MAL scores

Honestly, I am just a bit close to giving this a 5/10 when I decide on dropping it after watching the current episode (episode 4). You see, I am a fan of so many romance anime, it goes far and beyond to express how much I appreciate and enjoy a good romance, but even the original work of this anime (sourced from manga) says Love Status Quo. This type of theme is definitely not a first to me, a quite similar one is probably Karakaijyouzu no Takagi-san, I honestly stopped appreciating "Love Status Quo" kind of anime after having watched Takagi-san, tho I already looked into Takagi-san manga afterwards. The biggest reason I didn't give this a 5/10 is because the art quality and the plot trying to advertise an island culture so much and so well really showed me their efforts, to make this definitely better than "average" but however much that was it just didn't hit my spots at all... :/ dropped.