Are gains on the sale of crypto assets miscellaneous income rather than capital gains?

The National Tax Agency has stated that, in principle, profits earned by individuals from the transfer of cryptocurrencies are considered "miscellaneous income." Why is this considered "miscellaneous income" rather than "capital gain," which carries a lighter tax burden?

Income tax is categorized into 10 types based on the nature and source of income: interest income, dividend income, real estate income, business income, salary income, retirement income, timber income, capital gain, temporary income, and miscellaneous income, and establishes appropriate methods for calculating income amounts for each type. Income tax is broadly applicable to income in the form of economic gain, but not all income is taxed in the same way.

Even when earning income related to cryptocurrencies, the applicable income classification varies depending on the case.