Sure, but the context changes who "someone" can be. In this case, it's a personal open source project with pull requests open, where that "someone" means "anyone". We can implement the feature if we want, and for our efforts, we must expect as much in return as the original author received: nothing. Open source used to be abut collaboration, now it's mostly abuse.
If you want to add a feature to GitHub, that "someone" would neccesarily be a paid employee.
If you want to add a feature to GitHub, that "someone" would neccesarily be a paid employee.