We also always have a long field to get points because we lose field position on special teams constantly.
Nebraska's punt return unit is absolute dog shit averaging negative return yardage. I'm not sure that's ever happened at Nebraska. Hell, even Santino Panico and his fair catch game averaged positive yardage.
The kickoff return unit is getting penalized on almost every play. Both of these facets are forcing Nebraska to start behind the 8 ball and drive the length of the field. Hell Urban Meyer, love him or hate him, tracks field position and has ridiculous stats to support the percentage of converting touchdowns based on where drives originate. It doesn't matter if you're Ohio State or Bama, teams starting frequently inside their own 20, aren't scoring a lot of points.
Secondly, this Nebraska team has probably had more 20 yard plays called back than any team in the country. And many of those penalties really have little baring on the outcome of the play. 1st and 10 at the 45 is becoming 2nd and 25 at the 15 because of plays like a Foster jumping on an opponent 2 seconds after the whistle.
Lastly, Frost's scheme is predicated on big plays in the run game. At this point, the Huskers really only have one home run hitter in the run game, Mo Washington. He's been very close you breaking loose, but still needs more acclimation to this level. Devine and Bell lack and lacked the ability to go 70 yards on any given carry.
No faith in the kicker is also keeping scoring down. I'm pretty sure he has missed 4 kicks already, but that also changes the way Frost calls play and forces them to roll the dice in or near the red zone.
Turnovers were a bigger issue early. It's possible those won't be as problematic as Martinez and company get more experience.