You would have to  point me to where the judge says the issue of who created the characters is not important.
As I read it, it's just the opposite. She's saying there is no dispute Kirby and the other artists were creative types who contributed to fleshing out plots and characters, but that Lee created the basic concepts himself.
Take Spider-Man for example. Kirby contended that he gave Lee a character called Spiderman with spider-powers (wall crawling, a web shooter, 6th sense, super-strength) who was a teenage orphan living with his aunt and uncle. 
This basic idea is more or less the opposite of how Steve Ditko defines creation. As Ditko explained it he saw creation as how a very basic framework was filled out. Lee has been saying since 1972 that it is the basic ideas which were his, and that he gave them to the artists.
The judge accepts Lee's version of events, that it was Lee who came up with the basic Spider-Man idea, and all of the other basic concepts.
There is a huge dispute right there, and it's the core of the case. Kirby always maintained that he brought the seminal ideas to Lee per Goodman's  requests for super hero comic books.
We can be sure many IP lawyers will weigh in on this topic.