Open source isn’t about freedom

What does the term open source mean? Can you answer that simple question? The term is so
loose that almost anyone can interpret it in their own way. It just describes rules
for deciding whether software distributed under a particular license counts as open source.
Think of open source as a category. Only licenses that meet its
rules belong in it.
One such rule is the right to the source code. See Open Source I — What Is “Open Source Software”?

In other words, open source doesn’t mean freedom to use a program. Open source
is simply an economic view of free software. The key to understanding open source is
the license. It doesn’t matter whether a program calls itself open source. What counts is the license
under which it’s distributed. You can find comments on licenses on the GNU project site.
Richard Stallman sheds light on the subject in Why the Term “Free Software” Is Better Than “Open Source”, translated into Czech by Petr Přidal.