In a specific country, whose industry takes free open source labor from all over the world and then imposes its own cultural values.
Open source people from other regions provide the majority of code and have no say in political decisions. One might be tempted to say that they are slaves.
This is a default. If it offends your sensibilities so much, you can configure it to be something else.
Heck, I'd even go as far as suggesting that "main" is a more common word for non-native speakers of english than "master", making it more intuitive for non-US developers.
Open source people from other regions provide the majority of code and have no say in political decisions. One might be tempted to say that they are slaves.