Considering the history and foundations of the gaming industry it's ridiculous to say you have all Japanese developers. Bloodborne and Dark Souls are more popular examples of recent big name Japanese titles. The problem that's easily seen no is many of the titles being produced in Japan, simply aren't being localized here. And unfortunately there has been a change of focus for many Japanese devs when it comes to what audience they want to focus on. But many things tie into that, like shift in cultural aspects, change in market preferences,etc. I would say their games aren't terrible but more niche than your generic shooter. A lot of history and creativity comes out of Japan.