I use it in the context that you would use american. It can refer to a group or nationality, but it can also be used as a cultural descriptor, referring to the export of cultural beliefs and customs. This includes things like religion, but also includes language, customs, ethics, tradition.
For me the main difference is Linux only does something when I ask it to.
Windows does whatever Microsoft wants it to do.
Both have major usability issues. But Linux gets a higher tolerance level, because of higher trust levels.