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.
Well, you cannot judge or say people who invest in bitcoin are foolish. Because people who do that is the kind of people who sees bitcoin as their source of profit some might say it is just a risk but there are some who really earn profit in bitcoin thats why we cant say that they were foolish by the fact that they are really earning in bitcoin.