Like I said, they expect you to do extraordinary things, and it appears as arrogance. In the Jackson's Hobbit, you can't but feel it as the King denies time and again to help. You look closely, especially the capture scene, and they appear extremely protective of their community, because they view lesser races as nuisance, and not worth of their time. Which they have plenty.
In the end they however sees their mistakes and instead of hiding they go their way to help people, as all of suddenly they seem worthy. To human and other races eyes it appears as arrogance. Maybe there is also part of that they were the first race to live on Middle-Earth and in the Undying Lands. That they see themselves as the owners of the land. And in some places as caretakers.
It's curious that the Wood Elves let the Mirkwood to get in such a state, even though it's their forest. Why? Why Tolkien let the evil and darkness to seep in every part of the Middle-Earth, and the Eldar stepping back and closing in their strongholds?