Crazy or not there are still peopled investing even if the price is at the peak, I really think this is not the end of the increase of the price of bitcoin, and there are so much for us to go in a wide variety of value, and in my opinion if the last block isn't mined yet there is a possibility that the price would still increase.
Maybe someone known them as fools, it is hmupon yourself, don't let your surroundings affect your decision. In investing bitcoin maybe they have the reasons to invest but thats their business and we have different goals so I believe maybe you can call someone "fools" but we have different perspective in our lives.