Panic selling is what draws the price of Bitcoin so down to the drain. Any event which leads to panic selling of Bitcoin can be considered as a contributing factor. The news of a hacked exchange site, false news from governments, banks and the media, a Bitcoin advocate country later banning Bitcoins etc. All these factors contribute to the fall in price of Bitcoin on the market.
these factors that you mentioned are temporary factors, then the price recovers, but the scenario that we have today is lack of demand, we can not close our eyes and ignore the fact that we do not have demand, people were afraid because the price fell a lot and because many governments and central banks are implementing disadvantageous regulations for bitcoins, altcoins and ICOs.