Backgammon is a game of both skill and luck. It's far more skill than people realize. And just like the varying skill levels in any game, Backgammon has its own varying skill levels. Can a beginner beat an experienced player? Yes. Is this totally dependent on the roll of the dice? No. Poorly placed pieces regardless of the roll of the dice can almost guarantee you a loss. But more importantly, an experienced player will win the majority of the games against less skilled opponents (statistically speaking).

I don't know if the debate here is the luck of the dice and how that places an unfavorable advantage to the lower rated players as far as the ratings setup here goes, or if the debate is simply over the issue of luck vs. skill.

Here are some sites to check out.

Salar's site
Backgammon
Newsgroup Archive
Skill vrs Luck
Backgammon
balances luck with skill
A Measure of Luck
Various articles

My own opinion is that two players of equal strength playing at their best will be at the mercy of the dice roll at least at some level. However, since there have been world champions who consistently win even against highly skilled players, luck must be statistically ruled out.