Software sometimes faces the removal of features as it goes on in life. This is especially true of large, complex software with lots of users. Maintaining features through upgrades costs time and effort in development and support. Sometimes the justification is made that this or that feature or option is being removed and replaced with a permanent setting based on how many people don't use it, or the way most people keep the setting. This stands to upset as few people as possible.
The problem is that it does upset some people, and if you have thousands or tens of thousands of users, you're going to be upsetting a large number of people, however small the percentage is. That can get lost in the analysis. If "only" 35% of your users sort oldest-first, but the majority keep their lists sorted in the default newest-first order, you may be tempted to set the sorting option to newest-first permanently. However, if you have 100,000 users, you're about to cause problems for 35,000 of them. Some will adapt. Some will leave for software that still does what they want. Are you willing to risk those 35,000 users for the sake of not maintaining a sort option?
Mokalus of Borg
PS - For me, a lot of my software has an audience of one.
PPS - And when it doesn't, removal of features is not up to me.