People say this because they are ignoring the 90% of the factors they agree upon and so the remaining fractional differences loom large. Also photos are no substitute for real life.
Absolutely agree. I'm just saying that even if they were I think it'd be hard to measure attractiveness objectively because different people have different likes and dislikes.
However you probably are right that there are features that are considered attractive by almost everybody and that we just overlook those.