I _just_ rejected a PR yesterday from a contractor that did the initial checkin of a new project with no .gitignore file and all the build artifacts (everything

I _just_ rejected a PR yesterday from a contractor that did the initial checkin of a new project with no .gitignore file and all the build artifacts (everything under obj and bin directories). Why in the world am I having to protect the project from such things? I understand ignorance, but the person putting together the base of the project should know what the hell is going on.