The Open Source Initiative is a hypocritical organization that tried to trademark the term "Open Source" and was denied because they don't control the term and have no stewardship over it. Your interpretation is not accepted by the overwhelming majority of "experts in software engineering" (whatever that means), and I don't know of any way to quantify your claim either. What you are referring to is most likely FOSS, which is a more rigidly defined thing. Open Source, to most people, is a colloquial term that simply means that the source is available to be viewed.