Race/ethnic/cultural tendencies on 5-star an numeric eating scales have been studied quite a bit, and, yes, Europeans tend to give higher ratings for acceptable service (tending to give maximum ratings for “meets expectations”) while Asians tend to give lower ratings (tending toward middle-of-scale ratings for “meets expectations”).
I wonder how much that tendency is the result of Europeans having more exposure to "management by the numbers" kind of rating/review systems. Nearly everyone has held or known someone close to them with a job where a mostly meaningless customer review/rating/survey grade had an enormously disproportionate impact on their perceived job performance. The only times I'll ever rate something that isn't exceptionally good or exceptionally bad is when it is obviously tied to that person's performance metrics and they met expectations.
