Well this is a CAD software from a parallel universe, you wouldn't know what those mechanical engineers from that universe prefer.
I'm a physicist and I only used one CAD software occasionally. In the CAD software I used I had to clone primitive objects to use them in multiple operations. If I wanted to change one dimension I had to update all the clones. Simply the acyclic graph model works better for this than the tree model. (Also some operations were irreversible, that was absolutely inexcusable.)
In 3D CAD it's usually a parametric geometric modeling kernel. Everything is reversible and changeable, it usually it depends on an tree/directed graph.
I'm a physicist and I only used one CAD software occasionally. In the CAD software I used I had to clone primitive objects to use them in multiple operations. If I wanted to change one dimension I had to update all the clones. Simply the acyclic graph model works better for this than the tree model. (Also some operations were irreversible, that was absolutely inexcusable.)