The Maoists even won the Civil War in 2008 and deposed the King and monarchy.
That’s actually not accurate. The maoists did wage war but they didn’t win.
The one who ended the war was the ruling Communist Party of Nepal- Unified Marxist-Leninist (one of the first few communist parties already in Nepal since the late 90’s).
Error on my part there. The marxist-Leninists were established in roughly 1994, with the Maoists breaking off from them in 1995. The new elected government didn’t let them run for office and started persecuting communists and their allies, which led the maoists to make a 40-point demand to stop the persecutions, but the government didn’t listen and the peoples war started in 1996 when the Prime Minister was in India. Anyways, the Marxist-Leninists came to government power in 1997 and Nepal became the only nation to have a democratically elected communist government under a Constitutional Hindu Monarchy.
The monarchy was removed because the monarch at that time was the former kings cousin (due to the royal massacre) and people didn’t like him that much.
Add to that him taking up power by dissolving parliament (this is especially important in that the former king Birendra was responsible for establishing a formal parliamentary democracy in the 90’s; removing the beloved kings legacy was seen as a slap to his legacy).