Actually where rangers can make up lost ground is in the additional attacks adding additional STR+enhnacement+feats. at high levels this can be easily 15 damage (+6 enhancment, +3 feat, +6-8 stat) which is ~2[w] to 4[w]'s average damage depending on weapon (i'm just eyeballing the math, correct it if you feel so inclined)
if we look at level 29 fighter powers we have: (i'll ignore stances, since they really muck things up)
a 7[w] reliable + 1Xstr,enhancements,etc
a 5[w]+ 1Xstr,enhancements,etc, half on miss
rangers have:
3 2[w] ranged attack, essentially 6[w] + 3Xdex,enhancments,etc+3d8, half on each miss
and a 3[x] +1[w]->4[w] (assume same weapons in each hand)+2xstr+3d8,etc, half of the 3[w] on a miss, and if both hit you negate the triggering attack. (side note: i dislike this being the level 29 mellee power, its good, but it really doesn't feel like the capstone power of a two weapon ranger)
now the fact that rangers make multiple attacks makes them less black and white, if you miss on 2 of three shots, how does that compare to the reliable 7[w] fighter power. i don't know. But they have very great damage potential. But so do fighters. Damage is part of both their jobs, but they dish it out very differently.