There are reasons I come up with: Little known in Japanese community; there are many people don't watch English community even if they are fine to read English docs and send PR. There are almost zero article introduces rsync.net. Yen is weak for strong Dollar at this time, Overseas storage service tend to be slow from Japan. It's harder to be adopted by enterprises without Japanese reseller.
In my experience, rsync+ssh is slow with higher latency and price isn't attracting, so I haven't tried it yet.
BTW, Backblaze is great about PR thanks to HDD stats. News websites frequently advertise their name for free. They also have local reseller.
Relatively famous software reseller (repackager) but focused on individuals
Wonder if it’s seeing much adoption, this company looks to be kind of like Carbonite for Japan
That "accent" is due to our standard English teaching method that builds up an on-the-fly bidirectional translation layer on top of pure Japanese internal monologue. We're trained all the way from middle schools to college/University to do this complex rule-based word transposition and word-for-word substitution technique and that is unnatural as anything and slow as, like real QEMU. This is also why many dumb-faced Japanese people with some English skills are rather quick to issue and respond to fewer-words commands with highly technical expressions("don't lubricate [that] receptacle") but are far slower at returning verbal responses with higher word counts("I'm already 5 minutes into the future from the point I was to be there"), because they're doing it and it's not just a complex multi-parallel but also kind of an exponential time process.
I'm done with that method for better or worse, and I suspect my "tone" in literal English should not even be convincingly Japanese. But it's still way harder to do English, and for the vast majority of us who aren't demonstrably English speaking, it's just their precise translation skills coming with massive overhead.
For Japan, I'm pretty confident it's the language barrier. As in most countries, tech people in Japan are mostly males, and mostly are not very strong in the humanities and in social skills. This group tends to be extremely self-conscious about their limited English ability and generally avoids interaction with foreigners.
For Korea, I see a trend, but I'm not confident about the explanation. I see lots of bright kids at university, see them get hired at big tech firms, and see them enthuse about their work over beers. I don't see them interacting a lot with foreigners. My impression is there is so much going on within Korea that they don't feel strongly motivated to look outside.