Ele doesn't do crap for DPS. This isn't GW1.
I would love to see your numbers on this.
Rather than just spewing out claims - maybe try backing them up a little.
EDIT: Here are some of my numbers...
All tests done with no sigils, divinity runes (6x), berserker amulet, in Heart of the Mists on Heavy Golem with Steady Weapon.
Guardian Scepter (30/30/10/0/0 - Scepter +5%, +10% on Burning, Right Hand Strength || 2315 attack, 54% (69%) crit chance, 42% crit damage): 87 normal, 138 critical, 167 critical with burning on target.
Ele Staff (30/30/0/10/0 - +10% vs Burning, +5% in Fire, +20% below 33%, +20% vs kd, +10% > 90 self-HP || 2334 attack, 52% crit chance, 62% crit dmg): 118 normal, 254 critical, 277 crit while burning, 336 crit while burning and < 33% hp.
Against single targets guardian will average 142.2 damage per attack (assuming they're constantly burning). Elementalist will average 200.68. If we factor in attack speed (Scepter at 1 per .8 seconds, Elementalist at 1 per 1.4) you get guardian DPS at 177.75 and Ele at 143.34.
But the claim wasn't the elementalist was best at ranged single target. It was that they're good at ranged AoE. Factor in the fact that a fireball can hit up to five targets - scepter can hit one. Elementalist's DPS will overtake the scepter as soon as there is a second enemy in the 130 unit radius of the fireball. Which, in dungeons, is likely to be often.