Hello Mr. Das!
It is needless to say that present day communists in Bengal are poles apart from the tenets of theoretical communism. Nevertheless, the theoretical communism is also a faulty and Utopian hypothesis and implementing that in real life is absurd. Dialectical materialism cannot be the only measure of human behaviours, and class struggle is not the only component of history. Lots of other factors come in real life, which probably Marx failed to recognise in his Utopian ideology. I respect Marx for his awesome English, but his theory was a sheer gobbledygook.