I think being a fan is less important than being somebody that is willing to make the effort to understand the source material. I think JJ Abrams loves blockbuster action movies with no deeper substance or meaning like Star Wars or Indiana Jones, his idols are Lucas and Spielberg. That is fine and a valid way of viewing filmmaking and cinema in general. I am a huge, huge
fan of Alfred Hitchcock and most of his movies are thrill rides with no deeper intent.
Unfortunately, I don't think Star Trek works much as a blockbuster action/adventure rollercoaster movie. When it works best, it has science-fiction ideas and philosophy behind it. Unfortunately, that is the type of movie that JJ Abrams has no interest in making at all.
I don't mind that JJ Abrams isn't a Trek fan. Afterall, none of my friends or family are
. I mind that he isn't interested in the possibilities of science-fiction beyond emotional stimuli. He wants to make movies that make people feel and don't make them think. Unfortunately, I think that is utterly, perversely wrong for Star Trek. On the other hand, I think a director hugely interested in exploring science-fiction concepts would be ill suited to Star Wars as he'd lose sight of the swash buckling nature of the saga.