The difference between free software and open source isn't copyleft. Both free software and open source embrace copyleft.
From your writing I deduce you are of the opinion that open source is more or less equivalent to permissive licensing, i.e., using BSD-style licenses.
The actual difference between the two is that open source values the productivity benefits that come from sharing, whereas free software is primarily about protecting the freedom of people.
Mocking should be done carefully, and one should avoid mocking things one doesn't understand.
From your writing I deduce you are of the opinion that open source is more or less equivalent to permissive licensing, i.e., using BSD-style licenses.
The actual difference between the two is that open source values the productivity benefits that come from sharing, whereas free software is primarily about protecting the freedom of people.
Mocking should be done carefully, and one should avoid mocking things one doesn't understand.