When did Progressive thought become a bad thing ?

   Socially speaking, when did the concept of progressive thought become something worthy of questioning ? Progressive ideas and reasoning have permeated our existence from the beginning of time. Who wants their dentist to get out the pliers for a root canal . Where would modern medicine be? If the Wright Brothers were conservative thinkers where would modern travel be? What about the Pyramids or the Pantheon , the Space Shuttle , the internet , Google, all brought to us through progressive thinkers to push the boundaries of their respective limitations. Why now is the act of progressive thought under attack. Who would promote non progressive thought in their own life, could you tell your kids that's enough progress you've learned enough, no more exercising your mind , no need to keep up with the ever changing world.
    Put plainly the implementation of conservative concepts as a governing guideline would doom our society to a future of mediocrity at worst, and progress by chance and circumstance at best. More importantly the question is why? What would drive so many to silence progressive thought... fear. Fear of failing of being labeled incompetent and eventually irrelevant. The best way to suppress fear is eliminating risk of failing by limiting the reach of everyone's progress, some through religion which offers the security blanket of a predetermined destiny, and some fear the fight to overcome their own perceived limitations. In reality deep inside the mind of a true conservative must be all of the fear and anxiety of a fight they know they cant win.