I thought Ras Al Gul was pretty cool as well and considered him the 'main villain' much more than I did Scarecrow.
But Scarecrow did the actual "grunt work" in that he made the toxic fear gas, told the henchmen how to spread it around the city, recruited men for Ras, and physically infected Batman with the fear toxin and then tried to set him on fire with a cigarette lighter.
It is Scarecrow's love of fear and terror that is the heart of the story. The entire theme of the story is fear--Scarecrow's buried fear of others (after being bullied as a child, although it's never mentioned but implied in how he talks and acts) is what galvanizes his cruelty and sadism. Likewise, Batman's fear as a child (springing from seeing his parents die) is what motivates his reckless actions as a youth and then later on his altruistic ones.
The problem with Ras as a character, despite being quite well acted by Liam Neeson, is that he lacks a "script". You really never find out who he is or why he's doing what he's doing. Like Sam Raimi's Sandman, Nolan hesitates to demonize Ras, and by doing that (as well as never having a proper hero/baddie confrontation at the end) he robs the film and the audience of a proper catharsis. (Despite the admitted cheesiness of Batman's taking down Jack Napier with a giant gargoyle at the end of Batman 89, no one can say that there wasn't closure.)
Either way, it all comes down to fear. You can use it for good, as Batman does, or take what you suffered to inflict evil on others. What does Ras fear? Does he fear Bruce? Scarecrow? Gotham's criminals? What does he feel? None of this is ever said. He basically exists in a vacuum. That's why I think Scarecrow was a much better villain, and in my opinion the heart of the story.
You can’t just have your characters announce how they feel! That makes me feel angry!
