It's pedantic to say it isn't free when...it isn't? Plenty of smaller games make over $1 million. It's news to me that the concept of free is whatever the reader wants it to be. Free as in beer or free as in freedom, Unreal is neither.
Freedom in licensing definitely requires context and specification; an absolute view of freedom has little practical use. Game engines released, for example, under a GPL license may align with an absolute view of freedom, but they are useless for the vast majority of commercial games.