> and furthermore, this is because the drivetrain is ~always on the right side of the bike
While I'm sure this factors into things for advertisements for bike components, there is also just a general preference that westerners have for left-to-right motion. Not just in bike ads, but all ads with (or suggesting) movement. And also not just ads, but movies where directors believe left-to-right motion is associated with progression and right-to-left motion is regressive.
Research has shown that people like to walk counterclockwise (right to left) through supermarkets, which is why they are arranged like this for maximum profit.
Interesting that such a preference exists, and makes sense that supermarkets would therefore be arranged to support this, although as far as I can see this is only to extent of entrance doors typically being "off center" and starting you off to the right. The organization of the store - where the various produce/bakery/deli/frozen-food etc aisles/sections are located seems random from store to store.
It would be interesting to know how people behave if the entrance is to the left vs right. Would they change the direction they walked though the store, or would they just lose customers due to this "awkward" layout?
While I'm sure this factors into things for advertisements for bike components, there is also just a general preference that westerners have for left-to-right motion. Not just in bike ads, but all ads with (or suggesting) movement. And also not just ads, but movies where directors believe left-to-right motion is associated with progression and right-to-left motion is regressive.