I think the main reason is that it's one of those drinks that just never occur to you as a choice until you SEE
it sitting on the cart.
Most people have their "usual" drinks for on the ground, but those are the ones commonly offered in vending machines...and ginger ale is usually not one of those! So, when you see it on the cart coming down the aisle, you think, "Damn, that sounds pretty good!"
"In this present crisis, government is not the solution to our problem - government IS the problem." - Ronald Reagan
Comments made here are my own and are not intended to represent the official position of Alaska Air Group