So whose decision is it regarding the carrier editions of the 2014 X? The manufacturer's or the carrier's? Or both?
It's both really, but part of the decision was most likely made from a business perspective based on costs/available workforce. The decision is Moto's but their decision is a result of the carriers stupidity.
Disclaimer: I am not an expert, but this is my 2 cents.
From a business standpoint, updating the carrier editions of the 2014 X is not a viable business decision because:
Main reason for the decision: Carrier interference - The cost of updating a carrier device, as well as the manpower required, especially for a now understaffed Moto now outweighs the benefits. Sure, Moto would like to update the device, but that doesn't mean they can. They have X resources. Using their X resources, staff, budget etc. factoring in all the added cost and manpower of going through the process of updating a carrier device, they could probably manage to get 1 carrier device updated in about the time and hassle it would take to update 2 Pure Editions ASAP. 2014 and 2015 Pure for instance.
It's Pure (pun intended) business imo. There are only so many resources, they are focusing those resources on prioritizing Pure Editions heavily over carrier editions. Which from the business perspective (despite the bad publicity) is probably still the best option from the business standpoint.
It's partially about demographics as well. Compounding that, most people that care the most about updates, most likely own a Pure Edition in the first place.
Overall it's pretty much this (in my opinion):
Moto does want to update them, and I'm sure the Engineers at Moto want to as well. But that doesn't matter, management sees business, not your feelings. The carriers are standing in the way of updating the 2014 X's on carriers being feasible.
But wait! The Droid Turbo is getting the update?
Right, again, Business. I would personally be willing to bet my left shoe it is being updated for one of 2 reasons:
1) Moto is already in an agreement were they are required to deliver the update. Thus forcing them to allocate their resources their, and ironically probably leaving them to understaffed to update the 2014 Carrier X's.
2) Verizon sees the benefit of the update, and is actually working with Moto to make the process of doing the carrier update feasible, which other carriers are not doing.
That about sums it up.