How many Niedermayer games did you watch per season during those years?
I watched Niedermayer lots throughout his career, from Kamloops to Anaheim.
The biggest issue with Niedermayer is that New Jersey wasnt a great fit for his strengths. Scott Stevens was the opposite. But during the early 2000s (and late 1990s), put them both on Team Canada and there is no doubt who is the better player.
If you look at the periods '99 - '03 and '04 - '07, there is little difference in the quality of Niedermayer's play (whatever you happen to think the level of that quality). He was close to being the best offensive defenseman in the NHL in both periods. The biggest difference is that he was getting lots of PP time in the latter (including 5th and 9th among all NHL defensemen in '06 and '07), and very little in the former ( including 58th, 72nd, 77th among all NHL defensemen in '00, '01 and '02).
No offensive defenseman is going to win the Norris if they are 77th in PP icetime (probably mostly 2nd unit time).
In '01, Lidstrom had 43 PP points, more than Niedermayer had in '00, '01, '02, '03 combined. At ES Niedermayer was as good offensively as Lidstrom.
In '02, Niedermayer was 8th on New Jersey in PP ice-time.
The other power-play issue, of course, is that the Devils finished dead last in PP opportunities in most of those early 2000s seasons.
If Niedermayer had similar PP ice time as the other top offensive defensemen in the league, he very likely would've been a 1st or 2nd team all-star (or close to it) every one of those seasons in the late '90s and early '00s.
If he had played for almost any other team it would've been even more likely.