However, even if you're using an email based workflow you're still making a request to somebody to pull your changes into their tree, and I'm reasonably sure 'p

However, even if you're using an email based workflow you're still making a request to somebody to pull your changes into their tree, and I'm reasonably sure 'pull request' as a term for that came from the linux workflow. GH more provided features to formalise a common concept (which, even where I've disagreed with them on the details of how they formalised it, has definitely been a net win overall).