Hard to believe they are the team that won the most Bundesliga titles (behind Bayern Munich ofc). Hopefully they manage to secure themself a safe spot. I would miss them if they relegate.
They did win only one title in Bundesliga (1967/1968), but were very successful in collecting titles before that. Them being so poor for a long time is just the result of decades of mismanagement and other clubs catching up and overtaking. After the championship in 1968 things went downhill and they never were able to establish themselves as more than a mediocre team in Bundesliga at best. They always struggled a bit money-wise and there was always some agiation inside the club. They had some highs with good players and a functioning team/environment, but weren't able to back it up longterm.
In the 80's and 90's you could get away with it to some extent, since the smaller clubs were still even poorer in terms of management and finances. But since around 20 years, you have more and more of those smaller clubs making huge progress and if you don't get your act together you will be left behind. These smaller clubs like Freiburg, Augsburg, Mainz are here to stay, because they perform very well in all regards and there is no agitation at all. And then you have the clubs with big-ish money like Hoffenheim, Wolfsburg, Leipzig. There is just no place for clubs like Nürnberg in Bundesliga anymore, unless they change their whole structure by 180 degrees. And the fans and media also play a big role in it. You aren't the big and great Nürnberg anymore - you are a mediocre team with huge tradition, but thats it. You can't buy anything with tradition. The clubs, fans, media need to be more humble and stop living from past success. Have a fresh start.
Nürnberg is a lot like many teams from the good old days. Clubs like Frankfurt, Cologne, Gladbach relegated as well, but they were able to come back big time, especially Frankfurt and Gladbach. But you also have Kaiserslautern, who just filed for bankruptcy and play in 3rd league against amateurs of Bayern Munich. Stuttgart and Hamburg are the next clubs, that could go either way. Either they will be able to follow the route of Frankfurt/Gladbach and establish themselves as an above average team in Bundesliga again or they will probably be stuck in 2. Bundesliga or lower for ages.
It all starts with the management/coach and making good decisions, but a lot of big clubs just lack in this department. They have way more money than Mainz/Augsburg/Freiburg and are also able to earn way more money, if they are successful, but they are just too dumb.