Playoffs. Mogilny was a poor playoff performer. His scoring decreased from 1.04 ppg in the regular season to 0.69 ppg in the playoffs - a massive 33% drop. Although Mogilny one won Stanley Cup, there were at least seven players who were clearly more important (Stevens, Brodeur, Elias, Arnott, Sykora, Holik, Niedermayer). Being at best 8th on a Stanley Cup winning team isn't a great argument in his favour.
He's definitely behind Brian Rafalski in importance on the 2000 Devils too. So that makes Mogilny, at best, the 9th most important member of the team.
But Nieuwendyk was, at best, the 10th most important member of the 2003 team and that Cup win seems to have put him over the top...
Summary. Although Mogilny has a solid resume, he consistently falls short of the implicit standards for the Hall of Fame. If inducted, he would be among the weakest all-time inductees.
Great job, and it really serves to highlight the fact that the only argument for Mogilny's induction is his gaudy goal total in 92-93, but that was such a freak year, it would kind of like inducting Herb Cain for 44-43.