What you say is correct. However, Islamist Fundoos (they are called Fundoo in Pakistan!) have a different way of seeing things.
Its indeed correct, that a fundamentalist section of Pakis are trying to further Arabize Urdu which though is written in Perso-Arabic script, its 70-80% words are still of Sanskritic Origin.
Basic Goal is to deny/erase Pre-Islamic past of their existance. Recently MMA, religious paries in Paki land opposed teaching Pre-Islamic history in Pakistan.
Our Secularists are directly courting them when they also oppose anything prior to pre-Islamic India. Our Secular fundamentalists term those as "Communal".
This is NOT what even Nehru said. In a speech before Aligarh Students few months after partition he said: Indian achieved many great things in the past and that belongs to ALL of Indians. COME FORWARD AND PROCLAIM IT.
Fact of the matter is: Indian Secular Fundoos are blissfully unaware of the Islamism and its root, direction, Goal.