That statement is far from the mark.
Nobody in the US drinks under 21 as well.
Anyway I'm not asserting that no muslim has ever had alcohol or that there's no disagreement within islam about its use. But the idea that the majority of muslims are routinely violating one of the main proscriptions of their religion is an astounding claim you must be ready to back up right?
Kind of like how lots of citizens can (temporarily, occasionally, whatever) eschew some of the laws. I'd hardly consider Americans <21 a solid no-alcohol control group even if it were valid to compare adolescents to adults as control and treatment in any study.
I got the "Why do they have a word for beer?" from a Palestinian instructor I had, who was well versed in wining and dining. He was fairly cynical about the claims of "no alcohol".