I don't know how much clout the Skytrax honors have -- they get very little attention in the States, probably because no US carrier (CO possibly excepted) is a serious contender for them and because so few Americans fly globally.
I do know any survey dependent on a self-selected non-random sample rather than a proactive outbound sampling effort of random respondents is borderline invalid anyway. The Freddie Awards (which take the additional result-garbling step of applying a nearly incomprehensible weighting algorithm) and Consumer Reports car ratings are suspect for the same reason.
An obscure carrier like Air Tahiti Nui, or any airline that campaigns hard, can go out and achieve a Skytrax honor by stuffing the ballot box.
It's a shame the media circulates reports of Skytrax-type awards so uncritically.