Unless you speak Japanese, you are interacting with a small minority of people that care about interacting with people outside of Japan. Most people living there think it's great to fine, but still better than other countries and especially their neighbors.
The best analogy I can think of is asking a non passport holding American why don't they learn Japanese to attract business from one of the largest economies in the world.
But Americans still didn’t learn Japanese en mass when it looked like Japanese manufacturing was going to conquer the world. Just like they didn’t learn Chinese.
Learning a new language as an adult is incredibly difficult. I have learned Spanish to a basic conversational level and it has been a massive struggle for me.
My Swiss and German friends seem to pick up new languages super easily though. Likely this is because they learned a second, third, or even fourth language as children.
So, not impossible but it is good to acknowledged that this isn’t an easy thing to do and likely would be a generational shift kind of thing.
They have a very advanced and large economy (fourth in the world by size). Their problem is labor shortage, due to being one of the oldest nation in the world. They've already outsourced a ton of work, because there just isn't enough working age people in Japan to do all the work of their export-centered economy. If anything, they need to attract workforce (immigrants), not more businesses.
Interestingly, Japanese "learn" English in high school.
Most of them can read and write it passably, but can't speak it confidently and as per culture, if they can't do it perfectly they don't want to do it at all.
Do they even need to “attract business” there? Seems to me that as a developed country they have plenty of business of their own. And there are subsidiaries of western companies there. Yahoo is pretty big, and Google has a large office in Roppongi Hills.
It's just not a great investment option. ~1k hours of English is mandatory in Japanese K-12 education, and that takes one from nothing to at best infantile two-word sentences. People says usability from there takes another 1.5k, 3k, 10k hour rules apply, etc. All that to be an average immigrant tech worker rarely make sense.
