To support this you just have to take one example. Universities in western culture were built upon the basis that you could challenge the status quo and that you can question the establishment. This led to developments in social awareness and healthy discussion about the directions that people should take in life. However, nowadays, free speech is being taken away from universities. This fuel for inspiration and development is being eroded by the further expansion of the so called 'safe spaces'. This reality shielding mechanism is further exacerbated by the ever notorious SJWs who constantly undermine what it is to have free speech by shouting down others who disagree with them and branding them as racists or sexists.
This is summed up perfectly by the recent case of a Yale University master who was practically forced to resign as he advocated freedom of expression regarding what people should wear. He rightly said that people can wear whatever they like whether it offends someone else or not as it is there right as a human to do so. Some of his students disagreed with him and ran a hate campaign against him, forcing him to resign.
All of this leads to a world where you have to comply with the establishment. This leads to totalitarianism. There will be no other side of the debate and we will all live in fear of speaking out and expressing ourselves. This will end badly for the development of our race if we don't act now to protect our freedom of speech.
If you look at today's society it is clear that those who have an opposing viewpoint to the status quo are demonized and destroyed. Whether it be some reality TV star who voices his opinion on gay marriage, or a person calling radical Islam what it is, if it does not fit the majority mold they are destroyed. A great philosopher once said "where opinions clash freedom rings". It's hard to have opposing opinions when people are afraid to speak. And since people seemingly everywhere are seemingly harassed and ruined for giving their opinion I say it is being lost, but that it is lost.