The STL file literally means Stereolithography, and was created by 3D Systems. It is the intended use-case, and is limited like any other file format.
The fact many fabs avoid DXF is unit and format version ambiguity. However, the other reason is predicting bend deduction is often wishful thinking. Most high end CAD packages are fairly good at handling that mess for people, but often still have issues figuring out how features will deform.
CAD can also start to fail on large complex geometries, as even a simple single combo-tool g-code macro to drill, helical mill, and chamfer threaded-holes in a plate often is done by the time CAD/CAM path-planners finish/crash.
The fact many fabs avoid DXF is unit and format version ambiguity. However, the other reason is predicting bend deduction is often wishful thinking. Most high end CAD packages are fairly good at handling that mess for people, but often still have issues figuring out how features will deform.
CAD can also start to fail on large complex geometries, as even a simple single combo-tool g-code macro to drill, helical mill, and chamfer threaded-holes in a plate often is done by the time CAD/CAM path-planners finish/crash.
Best of luck =3