Japanese 8p Takanashi is only 7d on KGS. Is it hard for him to reach 9-dan level?

Takanashi Seiken (born in 1971) is regular 8-dan pro in Japan. He never won any titles or played in big leagues, such as Honinbo or Meijin. He plays on KGS as "takanashi" and his rank is only 7-dan. Too low for professional player, right?
The only example is sususu (Yang Huiren), but he is only 1-dan pro (and 7-dan on KGS).

Why the rank of "takanashi" is so low? I believe that even regular Japanese 8-dan pro must be able to stay on KGS 9-dan level. The main reason: he plays lot of rated games with kyu/low dan players - on big handicap. And it's very hard to beat them all.

I never saw him playing with KGS 8-9 dans. Maybe he prefers easy games.

What do you think about his strength, comparing with top KGS 9-dans, such as MilanMilan, doodle, bigbadwolf and others? Who is stronger?

Cornel was probably the strongest opponent of Takanashi on KGS. No chances for White, it seems.