A dual striking tempest fighter does almost as much damage. At first level 1d12+4/1d8+4 is quite possible. They are not even strikers. Rangers are strong strikers, but I don't find their damage at low levels to be unreasonable. Damage is what they're supposed to do. Tempest fighters are the ones over the top if you ask me, as they have the hit points, AC, and healing surges of a defender, and boast striker level damage.
A rogue with combat advantage can do 3d8+8 with an at-will at 1st level.
A sorcerer that can target multiple enemies can do 1d8+8 multiple times, and do more damage with a rider potentially. With a bit of luck, against a mere 2 targets that can be up to 2d8+32 damage.
A barbarian can get up to 1d12+1d6+5 with no strings attached, and more than any other striker on a crit.
If the stars line up, even a first level hellock can do about 3d6+15 damage in one round with an at-will.
This is what strikers do. It's not a problem, it's a feature.
And on the topic of ranger taking out minions, if that's what they focus on, they are doing a disservice to the rest of the party. Controllers and sorcerers are much more efficient at minion clearing.