[robomartin]

> what it would be like to try to understand and debug a PCBA for a 20 layer board that was just a bunch of code or text and didn’t have a schematic and some decent documentation.

That's a seriously important point. Open source is filled with just plain horrible code. EE's who are not generally trained in software development can deliver reasonable schematics. There's the potential for utterly unintelligible designs if they had to create them using software techniques. I have seen FPGA code that is most-definitely cringe-worthy and unintelligible without, as you said, stopping to draw a schematic.

One way to think of this --in terms of circuits, not FPGA's-- is that a schematic can stand on its own. A text based netlist, even if sophisticated, requires documentation and, more than likely, a schematic.