Why is Sonam Wangchuk, popular Ladakh activist, on hunger strike?

Sonam Wangchuk, the real-life Phunsukh Wangdu, is on a 21-day hunger strike along with thousands of Ladakhis, pushing for 4 pressing demands - inclusion of Ladakh in Sixth Schedule of Constitution, parliamentary seats for Leh and Kargil, a separate Public Service Commission, and protection against industrial exploitation which is harming the ecosystem of Ladakh and its tribal culture.