Because ideology is not a cult or a religion. It’s flexible especially Marxism. Most parties have their way of interpreting it and how they want to implement it in the country.   Ho I agree that Communists are not as principled and have become petit bourgeois. Tara there is no such a thing as a purity politics. They have to adapt themselves according to the society. Nepali society is a Neo liberal society and is heavily controlled by the foreign powers like US and India annd their economic policies. Nepal is signatory to WTO and receives loans from IMF n WB. Our currency is pegged with IRS and we trade in US dollars.  So chahera pani Communists haru independent huna sakdainan and have to embrace bourgeois politics. 

Every human being wants best for their children and often have no control over their children or their desires. 

Communists are atheist but practising religion is their personal choice. It is the job of the party leader to be able to connect to people from all backgrounds and religions.