The destruction of the Vishwanath Temple by Aurangzeb had also something to do with the fact that sciences (shastras) were taught there (what Aurangzeb called "satanic knowledge").
“On 17 jilqda, hijri 1079 (18 April 1669) the emperor learnt that in the provinces of Thatta and Multan, and especially in Banaras, the stupid Brahmins teach their worthless book in schools and both Hindu and Muslim students come to these schools from far off areas to acquire this satanic knowledge. Upon hearing this, the emperor, the preserver of the religion, issued an order to the subedars to demolish all the schools and temples of the non-believers. They were given strict orders to stop all types of idol worship and teachings of related religious texts. On 15 Rabi-ul-Akhir (2 September 1669), the emperor came to know that following his orders, his staff had demolished the Vishwanath temple in Banaras”.
Source: Saqi Mustad Khan (1947), “Maasir-i-Alamgiri”. Royal Asiatic Society of Bengal, Calcutta, 1947.
& Moti Chandra, Kashi Ka Itihas (1962).

Indian sciences were far ahead of Europe at that time (e.g. calculus, infinite series, and so on which were to lead to the scientific revolution a hundred years later). Destruction of temple schools where these sciences were taught was a big blow to India.
Below: Vishwanath Temple as drawn by James Prinsep, 1834

The temple plan drawn by Prinsep (the red is where the current mosque stands)