I guess finally Prachanda's luck might be better than Katuwal's or NC or UML. They might have some hidden strategies; so they might have opted for this decision.

Maoists might feel that staying in the government was not fruitful to them as they were not able to do anything while people were expecting a lot from them. If they are ousted from the government by UML and NC, they can blame these parties for the failure of government from doing anything. Maoists may take advantage again even when they have to go to street from the government.

I think if Maoist goverment fails, Girija will try to lead the government; I see very slim chance of NC letting UML to lead the government because NC is itself power hungry. UML ko haisiyat prime minister banna lai Raja lai nibedan diyeko jastai hunchha hola yespali pani, NC le pheri jilyai dinchha hola UML lai.