There is a reason that open source thrives in the niche of tooling for other software developers, and ... thrives less outside that niche. The target audience for software development tooling ascribes huge value to being able to read and modify the source of the tools we use. And for good reason, it's not just a principled stand; open source directly helps us do our jobs better.

But outside that niche, nobody really values this capability, and it's not a mystery why not. What good does open source do an accountant? Any given work-a-day accountant is never going to read or modify the source of their software. They just have no interest in that. They may have a computer enthusiast friend who has made a compelling case to them for why this stuff matters, so they may agree in theory, but they aren't going to do extra work or pay extra for this. It just isn't a direct enough impact for them.