> The article is mostly talking about things above the source code level though, including the economic and time investment needed to compile/install software, the sheer size of large projects, plugin/etc interfaces for easy extensibility,
A lot of that is made easier if the maintainer takes the time to publish all the ancillary pieces they use when making modifications to the project - secondary documentation, build environment setup support, etc.. Yes, there is always a certain level of inherent difficulty in making changes to software - apart from anything else, not everyone is capable of programming at all. But making sure you're really on a level playing field with the original maintainers in terms of tooling, environment setup, and available documentation, makes a huge difference.
A lot of that is made easier if the maintainer takes the time to publish all the ancillary pieces they use when making modifications to the project - secondary documentation, build environment setup support, etc.. Yes, there is always a certain level of inherent difficulty in making changes to software - apart from anything else, not everyone is capable of programming at all. But making sure you're really on a level playing field with the original maintainers in terms of tooling, environment setup, and available documentation, makes a huge difference.