F-2 was a silly project, but the idea was to build something a bit more "original" than strict license production like F-15J. Japan successfully executed E-767, C-2 and P-1 projects, which is probably more than most other countries can handle in a similar time period (i.e. India - Tejas). Problem with their projects is they are always over budget, faced with slim export chances leading to high unit cost, and plagued with quality issues (F-2 wing cracking, C-2 cargo door issues, P-1 sea water corrosion on wings and sensors, pretty critical issue for Maritime Patrol aircraft). If they manage a 5.5 gen fighter, they might be able to afford 20 at the exorbitant cost of $250 million each. In the end, their military projects are just like their post-90's consumer electronics, Galapagos products.