Models are oriented so that Z is depth, front to back, with X lateral and Y vertical. CAM is oriented with Z as the vertical axis and Y depth front to back. As a result, as soon as I flip over to the CAM workspace and select a tool, it becomes obvious that the tool is oriented along the Z axis, perpendicular to the default height axis for the model. It looks like there are ways to reorient various axis, but why should the user have to do that? Other hobbyist CAD/CAM software that I've used has always used the CAM standard of a Z height axis as the default for both modeling and milling/slicing operations. While it is commonly required to reorient the model to get the best angles for milling or printing certain features, even that sort of manipulation isn't as intuitive as I've found in other CAM/slicer applications. Again, the basic fact that milling tool defaults to an orientation 90 degrees off from the workspace vertical presents the user with something to work around right from the start.
