What else did you expect when the Japanese devs allowed for such a piss poor lineup for launch.
They are lucky that Sega had the sense to make a PS4 version of Ishin. The Dynasty Warriors stuff wont have as much of an impact considering the game has already been out for the PS3 for a while. And the Nobunagas Ambition Creation is more of a niche title in the sense that its not exactly something that garners large numbers to be considered a system seller and also has a PS3 version.
Ishin is the only real JP title that could possibly move systems though its fighting with itself due to the PS3 version going on sale at the same time. Considering the PS4 does not have BC its not exactly a MUST BUY now moment kind of thing and folks wouldnt mind waiting considering how piss poor the lineup of games looks right now.
*Edit
Truthfully Sony Japan and the pubs / devs have themselves to blame for any sort of lack of hype with the initial launch. They literally have nothing that is done by a JP dev PS4 only that states YOU MUST HAVE THIS SYSTEM. Granted the game wasnt perfect in the West at least there was Killzone Shadowfall for example. But Japan they have cross platform titles which means its fighting with itself even more so for the ones that the games were initially released on the PS3 first. There really isnt anything here that says BUY ME currently. Even Metal Gear will be cross platform and that doesnt come out till later.