Why should I pay hotel regulation fund tax when traveling to Hainan?

Explanation of government fund tax: The government adjustment fund is the fee charged by Sanya municipal government to tourists staying in Sanya hotels and going to Sanya scenic spots in order to enhance the government's ability to regulate the market and promote the development of Sanya's economic and social undertakings. The fund tax is paid by tourists and consumers (defined from Baidu Encyclopedia).