Bergeron and Krejci are the biggest culprits. Bergeron has 9 points. In 30 games, he would typically have 22-23 points in previous years. His defense is still fantastic, but his offense is atrocious.
Krejci would typically have 24-25 points, so he's also pretty far behind pace at 19 points, though not nearly as far back as Bergeron. A couple 2 point games and he would be back on schedule, unlike Bergeron.
Hopefully, they will just bunch all their offense into amazing second halves, but I wouldn't take a bet on it.
The utter lack of offense from anyone on the lower lines doesn't help either.