I agree that the comment that sparked this was talking about special purpose machines (tabulators, etc.) vs computers. I suspect that he went googling for computer history, though, and found the rather specialized definition of "general purpose computer" that the mainframe people created.
For those of us with a computer science, rather than an IT background, general purpose computer means Turing complete. And while doing scientific computing on a BCD machine may be like going to LeMans with your turnip truck, it's still doable and in an era when computers were rare for the average person, many would have been interested in doing it.