Why refuse? Because you have no idea who the person is, they don't have a history, and it is possible they want to take over the project to insert exploits into

Why refuse? Because you have no idea who the person is, they don't have a history, and it is possible they want to take over the project to insert exploits into it. An ignored project (un)maintained by an ethical person is better than a project just handed off to whomever. At the very least a slight background check should have been done to see if the user has a history of contributing and maintaining open source projects.