First thing, bitcoin can't die overnight.
Second, people are getting crazy about all cryptocoins not only bitcoin so this trend might remain same if there will be no more bitcoin.
People are investing in bitcoin because it has limited supply and no any government can shutdown bitcoin network. People find it much safer to store their wealth in bitcoin than in their local banks.
It conjures feelings of admiration, intrigue, and praise. We've become comfortable thinking that love and attraction is about being in awe of someone. That exact behavior is the same reason we lose interest in people who show too much interest in us.