I'm not scared off by long stories; I've read some long ones that held my interest through every chapter, and I've also written some long ones. I think it depends on the story, though. Why is the story so long? Is it because there really is just a lot of story to tell, or because of too much fluff/filler in the middle, or because the author didn't want to let go and took it past its natural ending point?
As a writer, I think the thing to ask yourself with every scene is, "What is the point of this?" Every scene should move the story forward in some way, whether it's developing the plot or developing the characters. If you can't justify why the scene is truly important, take it out or don't write it.
My stories tend to run long. I never start a story without an ending in mind, and I just write as long as it takes to get to that ending. I think my problem with my super long ones is not so much pointless filler as much as just too many subplots, too many ideas in the same story. I tend to think of BIG ideas, and I need to learn how to simplify so the stories don't take so long to tell.