I think the reason these don't come to psn is because they already released all of these games for ps2 (with online play through kddi) in Japan.
So they would more or less be releasing the same games for psn (free online play) opposed to kddi which you have to pay a monthly fee for.
People would be like, "what the fuck?" Or something like that, that's my best guess of trying to make sense of it.
That could very well be it.
So, I guess unless KDDI terminates their contract with SNKP, we probably won't be seeing any of those Neo-Geo compilation games on PSN for awhile.
Sounds to me like the old "Screw the rest of the world- let's focus only on Japan" excuse.
Then again, with the most recent PS3 models having phased out PS2 backwards compatibility, I have a feeling SNKP's games will wind up on PSN sooner or later (in Japan, at least- the rest of the world may be left hanging for a while).
Still, I would like to see some of those games arrive for PSN worldwide sometime down the road (especially since, statistically speaking, even the DS and PSP are clobbering the XB360 in terms of sales in Japan).