> The rest of the team observed them in admiration.
They should have been included in building base, they also should spend time learning what state of the art is (since, as article says, they had time before requirements started flowing)
Then we have the replaceability factor. It's not rare for someone to try to secure their spot by making themselves irreplaceable, and one way of doing this is by being the only person working on a project or the vast majority of the codebase. I'm currently onboarded in a (previously) 1-man project and I find myself learning why they designed things like that instead of learning the framework and best practices.