Elves in DF strike me as a lot like elves in many other games and fantasy stories, except without the benefit of an elf-friendly narrator. At the best of times they seem to be hypocritical, arrogant jerkwads who can't back up even half of the cool stuff they're credited with. They get away with plenty of evil, or at least unpleasant, stuff because they're the designated good guys, even though they don't act it.
Consider the Combat entries for Elf and Goblin in the D&D 3.5 monster manual.
Elves are cautious warriors and take time to analyze their opponents and the location of the fight if at all possible, maximizing their advantage by using ambushes, snipers, and camouflage. They prefer to fire from cover and retreat before they are found, repeating this maneuver until all of their enemies are dead. They prefer longbows, shortbows, rapiers, and longswords. In melee, elves are graceful and deadly, using complex maneuvers that are beautiful to observe. Their wizards often use sleep spells during combat because these won't affect other elves.
Being bullied by bigger, stronger creatures has taught goblins to exploit what few advantages they have: sheer numbers and malicious ingenuity. The concept of a fair fight is meaningless in their society. They favor ambushes, overwhelming odds, dirty tricks, and any other edge they can devise.
Goblins have a poor grasp of strategy and are cowardly by nature, tending to flee the field if a battle turns against them. With proper supervision, though, they can implement reasonably complex plans, and in such circumstances their numbers can be a deadly advantage.
Pretty similar tactics and general sense of fair play, which is none at all. The elves are admired for the same thing the goblins are cursed for, apparently for no better reason than they're elves.