You missed the point. It appears the first 3 games were decent based on their scores, but it was apparently 2 years between the original and Yakuza 2, and 18 months between Yakuza 2 and 3. It looks like it will only be a year between 3 and 4, so it will be impressive if it scores as well without being dinged for poor execution or failure to innovate.
That's some pretty silly logic you got there. You do realize Yakuza is a Japanese game, and the time between the first and the second was only a year in Japan right? You do also realize that Yakuza 4 has been out in Japan since March 2010 right? Looking at the time between releases is pretty retarded anyway. If the gameplay and story are great, it'll get the same praise as the other installments.