Ball Bearing Spool Mount

I used the top portion of this spool holder to make a desktop holder that sits beside my K1 Max. Why did they put the spool holder on the back??

https://www.printables.com/model/668224-creality-k1-top-spool-holder-with-roller

I built the lower support from a “Tabula Rasa” approach. I made my design in OnShape. It printed fine without supports. If you use OnShape, my OnShape design is here:

https://cad.onshape.com/documents/f50da29612964d6a2eefbc52/w/bbe3201f16a1b699b8d25807/e/9ab6e0d8d3a65d9418e41bb2