"Really, it's inconceivable someone will ask 'Why'." Really, it absolutely is not. If someone was doing something for you, and then decided to stop doing it, although they were perfectly within their rights to do so you were inconvenienced by their decision and casually asking why the arrangement is changing is completely natural. Complaining about it and dismissing the resulting answer would be verging on rude, though.

Arguments above like "they weren't inconvenienced because they were already making their own way into the office 40,000 years ago" are utter nonsense. If I got a dishwasher two years ago, then it broke, that's inconvenient, regardless of the fact that I presumably used to get along with hand-washing just fine. Simple as!