It helps make sense of it all, but I don't think it's strictly needed. It's good for showing the contrast between Nagato as she appears in actual Haruhi canon and how she appears here and in the Dissapearance movie.
I liked it too anon.
Too many people expected it to be S3 when it was never going to be that.
People who hates it are those who prefer Yuki than Haruhi
AKA the oddballs of this fandom
I don't disagree, but most of the unwarranted hate is from using well established characters and the have them act almost completely different. Haruhi was really the only character who was written the same.
It should be been all about Asakura. Fuck those side characters.
My only real problem with the show was that Nagato didn't read anymore. She was doing that in the movie not playing with her PSP.