“computer code by its purpose and by its use properly belongs under patent law rather than copyright law”
I’d say it kind of depends. If you are creating an entirely new process or way of doing things or architecture, then sure, that should be patentable. However, in writing the code you are simply using an existing language to issue a set of instructions. Whatever new thing you created might be contained or described by those instructions, but the instructions themselves seem more like a matter for copyright law.
No more true than a different type of wiring harness for a vehicle should be considered a language...which is true to the same degree as the wiring of components delivers power which acts to instruct one component to perform an action.
I have far too much experience in both analog and digital electronics to be bamboozled into assigning any credence to the notion that digital instructions are entitled to any intellectual property protections which analog instructions are not.