The 16GB base model wasn't sufficient for the 6/6+, and is even less sufficient now with the 4K videos and 50% more megapixels (which I imagine would be on by default).

In the previous models (5/5s, 4s) the base model provided enough memory for doing most things comfortably. Now you actually HAVE to get the intermediate model to do anything useful (unless you're in masochistic mood). So the intermediate model (costing $100 more) becomes the entry level model.

I would even go so far to say that the 16/64/128GB memory gradation, coupled with the slippery 6/6s (slip and break more often ==> more AppleCare purchases and/or service repair costs) are intentional.

I understand capitalism and all that, but this is just pure greed and they're not doing much to hide it.

Sometimes the mere existence of the base model causes some problems that can't be fixed with the existence of an upgraded option. This is a consistent problem in an enterprise environment. The base model is always the one purchased more frequently whether through BYOD or enterprise owned devices. This means that support staff has to spend a lot of time working with users to manage space.