> Why charge your customers extra for something that costs you literally nothing extra?
Because (1) you can, and (2) it maximizes profit.
> Why not do the same for everything?
Because of estimates about what people will accept not having in the base model and what some will be willing yo pay extra for. Why do you think there would be some other principal at work here?
Welcome to capitalism, it seems you are new here.
> Why charge your customers extra for something that costs you literally nothing extra?
Because (1) you can, and (2) it maximizes profit.
> Why not do the same for everything?
Because of estimates about what people will accept not having in the base model and what some will be willing yo pay extra for. Why do you think there would be some other principal at work here?