I don't know about what others are thinking, but imposing tax on bitcoin transactions or revenue looks like a positive change to me. If bitcoin is taxed by some government, that means, bitcoin become legalized in that country. I am sure bitcoin users won't mind paying a certain percentage of tax from their trading revenue to the government and get a legal status. While majority of the governments have not taken a step to legalized bitcoin, Korea's case can work as an example to them and they might follow the same route by providing a tax framework to their citizens as well. That will be a positive move and acceptability will grow higher for bitcoin. That means price of bitcoin will also grow higher. I am sure if it happens, it will leave a positive impact on bitcoin and crypto world as a whole.