>Could they have purchased the hardware instead? Probably

Uh, from the article:

>We use many off-the-shelf development boards and even provide support for a number of these boards in Hubris. These are great for many use-cases, but less great when we are trying to model specific circuits or subsystems of our product designs. Second, we have numerous examples of custom boards that were built simply because we could find no useful OTS (off-the-shelf) alternative.