I think that the real reason is that the ideology of cryptocurrencies is not acceptable for banking systems and the governments in general. They really can't be for the market, because it will eliminate them. What they can is either confront it by spreading fud, court and regulation threats or by trying to take control over the market by investing in top coins as well as trying to create their own. So yes, I think it is more of manipulators thing than hacks, because the former is related to panic selling and big rival players.
