I think many of the alt coins may in fact disappear but there will be new ones to take it place and the alt coin space will eventually be filled with quality projects and tech advancements.  People will always want to be in alts so they can gain more Bitcoin.  One nice alt coin pick gains you many Bitcoins if you put down a half decent amount.  As always you can get Rekt as well.  I think alts will always be around.  Maybe just not these ones.