To be fair here: It's on both parties to be mature about this interaction. It is the responsibility of the developers of the project to be responsive though.

To be fair here: It's on both parties to be mature about this interaction. It is the responsibility of the developers of the project to be responsive though. I would just like to add that many open source projects you are looking at are funded by companies with salaried developers (all of the ones you listed are). These companies have customers that come first. Their has to be due diligence on what goes in to the code base. If you are ready to submit a pull request to a project and the developers are receptive to teaching then view it as a learning experience. Try to understand both sides though.