In bear markets, many people think like you do (ie great depression, 2008 housing crash, etc). Those that are good with their investments see it as an opportunity.
Nice illustration huh, anyway, for whatever reason the market will always move whether up or down in terms of their price value. Depending on the volume of each coins/altcoins have. Besides, every time there is a decreasing value happened many are often got panic in it which lead them to sell their coins even they knew in the end they've loss anyhow.