I'm not any kind of an academic on the subject, but I'd guess a combination of lack of resources, and general lack of scale. Japan simply was not that big a co

I'm not any kind of an academic on the subject, but I'd guess a combination of lack of resources, and general lack of scale. Japan simply was not that big a country and even if you assume they had a disproportionate amount of intellectuals or amount of advancement per individual, they're a tiny tiny fraction of the size of the US, the US simply could be working on a lot more projects at once, and even long-shot ones that might not bear fruit, and they were working on the shorter-term ones at the same time. And that size factor also translates into much poorer availability of the strategic materials that are necessary for a lot of advanced research. After Midway the Japanese military really shifted into field-expedient mode, you can see it even in things like the quality of their small arms production, they started cutting every corner that it was possible to safely cut and then some. At that point I imagine that a lot of the advanced research was cut hard unless it was really really important (iirc they still had, for example, a nuclear program) or seemed likely to bear immediate fruit. The pacific front was really over when Japan didn't get the US carrier fleet at Pearl Harbor and it was definitely over after Midway, everything after that was just stubbornness. Same as the European front - there was really no chance of victory once the US shifted off a market-economy to a command-economy focused around war production and you had an industrial nation 2-3x the size of everyone else sitting 2000 miles away (which, realistically, might as well have been on the moon as far as Axis force projection) pumping war materiel into the battle. The US could build tanks faster than the Germans could blow them up, they could re-tool the Russian industry to modern standards, and they could build ships faster than the Japanese (or German u-boats) could sink them, all at the same time. In that sense even if they had gotten the pacific fleet, the US probably still could have won in the long term, it would just have taken years longer. It's a "what if the germans had actually taken moscow" counterfactual... it probably still wouldn't have changed anything given the biggest factor, which is an untouchable foe sitting on the other side of the planet pumping out war materiel while you run out of your own resources. But yeah in general the role of the military in Imperial Japan is very interesting... the army and the navy both had their own armies and navies and air forces, and they basically were in competition for the favor of the emperor. It wasn't quite what we think of as a modern professional military where everyone is at least theoretically "on the same side", the armed forces VERY MUCH did not like each other and would go out of their way to screw the other over. I could definitely see some disdain for eggheads, or refusing to adopt a technology because it came from the wrong branch too.