[csense]

The software world does not solely consist of large, safety-critical projects.

Picture a single person or small team releasing an open-source project, it generates little developer interest and a community fails to start, and the original author(s) move on.

Fast forward 5 years or more. The code's floating around the internet, but nobody's left who understands it well enough to explain why it breaks with a modern toolchain. Requiring people to use a compiler -- and possibly an entire operating system -- of that age will deter people significantly from using that project.