The term has been around and in use for quite a while now, and certainly in widespread use around the DE&S area. As FILO points out, it is intended to be all inclusive, and certainly works quite well for UAV/RPAS etc.
I guess for some contributors out there in the ‘real world’, where they deal with things not much more complex than a Cessna, then change can be difficult to deal with. Meanwhile the rest of us get on with dealing with some fairly complex military air systems.