That is not to say that the theory holds water. Flat Earth theory is also notable and has a wiki page, even if blatantly wrong. There is no hyperboloid Earth theory wiki page.
Among mathematicians, I wouldn't claim that "Fields medalist disease" is an unusual term, though this term is typically meant to mean "some mathematician got a Fields medal, but did not prove any other deep mathematical result afterwards". There also exists the much more derogatory term "dead wood" for mathematicians who once proved highly celebrated results, but after they got tenured, no they didn't manage to prove anything deep anymore."
Concerning the "crackpot undertone" of "Nobel Disease": lots of mathematicians know the names of achieved mathematicians who got into some eccentric ideas ("eccentric" in the sense of "outside the Overton window") once they got older.
Famous examples for the latter point are Serge Lang
> https://en.wikipedia.org/w/index.php?title=Serge_Lang&oldid=...
or Anatoly Fomenko
> https://en.wikipedia.org/w/index.php?title=Anatoly_Fomenko&o...
We don’t do that with Fields medal winners. Mainly because most people don’t even know what a Fields medal is. I can’t write a headline that relies on Elizabeth Moon’s or Stanislav Smirnov’s borrowed authority because the average joe doesn’t know who they are. But that definitely happened with multiple Nobel prize winners because the Nobel prize is that well known. A Nobel prize winners opinion on race science is inherently newsworthy.
You know how we know the Nobel is in a different league to these other awards? Because when you explain what a Fields Medal is to someone who hasn’t heard of it, you say “it’s the Nobel prize for math”.
And the fame of the prize leads to attention, which in the words of Milton Friedman, is “flattering but also corrupting”.