There are always impatient people or investors in urgend need of money who sell their assets like stocks or Bitcoins. Even at the price of a loss. There can be many reasons for that (lost job, need money for health care, etc.).
I think Dealing with it, bitcoin is not enough to use (especially in 3rd world countries) you can live with bitcoin only. Currently we still need money to pay most of the goods.
Because although no matter how bullish you are in bitcoin, some people still need fiat; perhaps to pay bills, to buy random items, to pay for some kind of emergency, because they lack fiat, the stuff.