You guys have some unrealistic expectations, that's why you're disappointed.
He has 14 goals in his first 38 pro games and he wasn't getting prime minutes last year.
For peer comparison, Vesalainen has 5 goals in his first 33 games.
Cytil had 14 goals in his first 55 pro games.
Poehling had 3 goals in his first 13 AHL games (Granted, he had an NHL hat trick but we're talking AHL production)
Tolvanen had 15 goals in his first 58 games and only 1 total this year.
Just a little perspective for those who are "disappointed" with Yamamoto's production. If his production is mediocre then all the forwards drafted right around his spot have been horrendous, which is obvious hyperbole on both accounts.