My impression is that Amazon is kind of biased in that regard. There are valid reasons to keep the warehouse logistics in-house. And they did invest a lot of energy into that. It just bugs me that Dropshopping was never really pushed while the logistical powers to be ever so slightly pushed against it.

Nothing wrong with that, but it could very well be the first clue that Amazon is behaving more like an incumbent than a disrupter as described in the Innovator's Dilemma.