You talk about gatekeeping, when most people don't know the difference between git and GitHub, making your first PR is difficult if you have never done it, navigating a repo to look for your first change is difficult. And yet the status quo is that people should just figure that out.
You also talk about gatekeeping when in the many makerspaces I have been to, there are always highly experienced people who tinker on their own terms but rarely pay it forward, meaning they keep their knowledge. The reason for this is due to the often anarchist structure of maker spaces. Things happen if they do.
Sometimes there is an organized class. Most of the times, not. So you come in every week and people are just sitting around talking about the rules of keeping the space clean and when dues are due.
The concept of the hacker space and maker space is great. The execution leaves a lot to be desired. I consider it a 1.0 of a technical movement.