I think this can said of many devices or solutions. I see people that work within a single browser window to do all their navigating, rather than opening multiple tabs or even just multiple windows. Or they will only use one way of finding something on a computer, or always use only the mouse instead of a quick key combo (I'm a keyboard person vs a mouse person, if that tells you anything about me). And I don't understand how someone can get by with one browser window or tab.
People by their nature are going to work within a limited amount of features available to them, because not everyone is a dabbler and not everyone has or wants to spend the time absorbing, accepting, using features that are not already second-nature habits. I discovered a trick a while back on a phone that would do a redial, and I use that occasionally. But even though I know how to look up someone's extension on the phone set, I will reach for my directory instead. When checking voicemail, I will also type in the required codes rather than press a button that does it for me. Not that quirky of me, I just also have preferences, I like seeing the name of the person and their title, which is hopefully up to date.
When ti comes to things being "hidden" from the company at large by the tech team, I think there may be more than one story there. I think that makes sense some of the time, but other times, I think it could just be that it is not a priority for the company to ensure widespread knowledge on the maximum number of features. As well as bad communication and bad management. Depends on the users and what the features are. But I am NOT in telco, and that's just my perspective.