I believe the following example does a good job at illustrating how the movement to avoid offending anyone with un PC language hinders free discourse and the exchange of ideas.:
For example, in a satirical example of so-called PC speech, the sentence “The fireman put a ladder up against the tree, climbed it, and rescued the cat” might look like this:
The firefighter (who happened to be male, but could just as easily have been female) abridged the rights of the cat to determine for itself where it wanted to walk, climb, or rest, and inflicted his own value judgments in determining that it needed to be “rescued” from its chosen perch. In callous disregard for the well-being of the environment, and this one tree in particular, he thrust the disabled-unfriendly means of ascent known as a “ladder” carelessly up against the tree, marring its bark, and unfeelingly climbed it, unconcerned how his display of physical prowess might injure the self-esteem of those differently abled. He kidnapped and unjustly restrained the innocent animal with the intention of returning it to the person who claimed to “own” the naturally free animal, but it immediately fled his grasp, having withstood more insult and injury than it could bear.