Agree with all of your post except those two small points. I genuinely don't see LH as "among the best in Europe". There are so many European airlines which I think are actually better (TK, OS, LX, AZ, SU, heck even BA is better than LH in my view). In fact regardless of the segment I look at (short, medium or long haul, Y, J, etc) I can't think of anything they do really well except apparently the F terminal and F lounge at MUC and FRA (on their F, I have no direct recent experience but have quite a few friends who use them regularly and are far from wowed despite the tasting menu, lounge notwithstanding but ok, F might be the exception).

On the second, "the airlines people prefer" would be fine but my sense is that it is mostly "the airlines people are used to" which is not quite the same. Again, to only speak of what I know, ranking the BA CCR above the AF P lounge is ridiculous as is ranking BA premium economy above VS's or even AZ or AF. And again, ranking the BA business lounge over the TK one is again absurd as is ranking SK above AZ.

This being said, I am not disputing your general point that "law of average" helping, you do get a number of correct directional tendencies (including the fact that there is nothing AF or KL are quite industry leaders at), but it is just a case of remembering that Skytrax are so imprecise about the methodology they use in particular lack of transparency in the sampling that the bias that is inherent to the study simply cannot be fully evaluated/understood.