I find the guys locally who call themselves unlucky are the guys who regularly don't have tokens or ways to modify their dice, and/or find themselves out of position on a regular basis (easier to blame the green dice when they have no red dice on a turn).
Yes. This.
One thing it took me a while to realize as well is that if, on the initial exchange of fire, you have a single one of your ships shooting at the opponent, and his 3+ ships all have shots back... You're gonna have a bad time. And, until you notice why it's happening, you might chalk it up to "bad luck".
I also find that, unfortunately, sozin's lady luck site paints a very poor portrait of each player's "luck" throughout a game. I don't think I've seen a single game where (according to the site) luck favored the loser - ie: no one has ever overcome "unluckiness" with good flying.
That said, mitigating the effect of bad rolls is a key part of the game. Be it with better positioning, arc dodging, token stacking, re-rolls, engineering the initial encounter, etc.