This article talks about the fact that adding an additional shipping charge is painful after years of conditioning customers to expect that charge to be $0.
Yet it's not as if retailers have had to eat 100% of that cost in the absence of a separate line item on the order. Consumers are aware that shipping charges are often priced into the base cost of the items, especially from online-only retailers who don't need to maintain the illusion of having the same price in store and online.
Personally, I like the idea of baking the shipping cost into the price of the item. (I also like the idea of baking gratuities into the cost of restaurant meals.) And if a company then wants to offer some discount for quantity or loyalty or whatever, that's fine.