I'm not sure what person or specific comments you are referring to but my point here was simply that there can be a variety of reasons why a phone is cheaper or more expensive than another including features, support, etc. Also, the "support clock" starting when a phone launches and not when purchased seems to be the industry norm.
As I previously stated, a reason the 15 has a lower retail price in year two than in year one is because it may have approximately one year less support. Reasons someone may pick the 15 over the 16e could be the better camera setup, more desirable color options, etc. and they don't care about the year or so less support.
Related to all of this, what exactly is Apple doing that is "wrong" or outside the norm here? What am I missing?