You're quite unfairly singling out openscad. It's a different kind of modeler, it's script based not gui based. Sure it won't transfer directly to gui based modeling, but things like knowing how to lay out parts and approach designs do transfer over. I also think that people who use openscad have a better idea of how powerful 'parametric' modeling is. I think this is mostly because many of them have a programming background and are familiar with parametric functions and modules. I've seen so many people using fusion 360 and other programs, claiming they are so good at parametric modeling yet completely missing the main strength of parametric modeling. They assign constants (numbers) rather than variables for all of their dimensions. Just changed your model to use m5 instead of m8? Have fun going back and changing every screw hole.

On the flip side I could jab back. How transferable is fusion 360? It's not like it'll give you a better idea of how to edit your printer's firmware. They both transfer in different ways, and for a hobbyist, you don't need your cad skills to transfer between 50 different cad programs.