The steel mill wrote the software, they've got a couple guys writing C# for an ASP.NET app that runs their custom CRM and pushes orders, CAD files around, keepi

The steel mill wrote the software, they've got a couple guys writing C# for an ASP.NET app that runs their custom CRM and pushes orders, CAD files around, keeping the workload consistent so that you don't end up with a bunch of parts in a row that all need the largest gantry crane at the same time, ensuring that patterns cut in-house are ready on time, making sure that the shop knows what color paint goes on each part, and so on. And that's not even getting to the custom automation software that runs on their PLCs and so on. Sure, in that specific example they only have about 5 out of a couple hundred employees who can write C#, and maybe 10 who can program PLCs, plus some contractors like myself. But your definition of "software company" was effectively "dependent on custom software to operate", and that's been true of every single one of hundreds of automotive/furniture/aerospace/heavy industrial manufacturing plants that I've been in throughout the past 10 years.