whether the cause of this is happening, is it something to do with the decision of the south korea government?
Decisions from south korea do not affect the price of Bitcoin. Bitcoin is down because many traders and whales decide to sell their Bitcoin shares to invest in ETH. Upcoming ETH will hard fork that is why Bitcoin prices are going down.
Just don't be so much worry about the price decreasing, it happens and will happen even in the future that some traders will really switch to other form of investments such as what you have said, but one thing is for sure it will increase although not now but maybe tomorrow, after a month or year just hold what you have.