> If somebody doesn't want any competitors they should have read the licenses and understood them, and not simply used open source as a buzzword for marketing purposes.

One should always read software licenses before installing a dependency, regardless of how a particular project is marketed. This would still be necessary even if companies weren’t using the term “open source” to refer to this type of license.

People make it sound like companies are out to confuse you by calling it “open source”. If you’re the kind of developer that blindly uses a piece of software because someone claimed it was open source without doing due diligence on how it can be legally used, then you deserve whatever consequences may arise.