Here's Charvaka's criticism of Vedic Dharma in 600 BCE :-
"The three authors of the Vedas were buffoons, knaves, and demons. All the well-known formulae of the pandits, jarphari, turphari, etc. and all the obscene rites for the queen commanded in Aswamedha, these were invented by buffoons, and so all the various kinds of presents to the priests, while the eating of flesh was similarly commanded by night-prowling demons."
"There is no heaven, no final liberation, nor any soul in another
world, Nor do the actions of the four castes, orders, etc., produce any real
effect. The Agnihotra, the three Vedas, the ascetic s three staves, and smear
ing one s self with ashes, were made by Nature as the livelihood of those destitute of knowledge and manliness."
"While life remains let a man live happily, let him feed on ghee even though he runs in debt ;
When once the body becomes ashes, how can it ever return again ?
If he who departs from the body goes to another world,
How is it that he comes not back again, restless for love of his kindred ?
Hence it is only as a means of livelihood that Brahmans have established here
All these ceremonies for the dead, there is no other fruit any where."
And yet Madhavacharya included his vicious and pointed criticisms it in Sarvadarshan Samgraha.
https://archive.org/stream/thesarvadarsanas00madhuoft#page/n37/mode/2up
There is a long list of people who have criticized Hinduism, bashed Brahmins like anything and yet were able to spread their doctrines in India, infact many Brahmins themselves took up those doctrines. Indic tradition allows for criticism and debate. This is central to the Indic tradition. Plenty of Buddhist, Jain, Sikh polemics mocking Hindus for their stupidity. & vice versa from Hindu side to these traditions, see Dayananda Saraswati's Satyarth Prakash.
Are there any parallels like this in Islam ? Amir Khan made a mockery of Hinduism and Lord Shiva , yet he made 500 crores in that movie When he talked about intolerance, Hindus responded by boycotting snapdeal. Do Muslims take to the criticism of their religion lightly ? Remember the rioting and burning across the world over cartoons and the innocence movie ? In BD right now, critics of Islam are being hacked in broad day light. Happened in Charlie Hebdo. Something called as "blasphemy law" in Pakistan which is used to harass and convert minorities by putting false accusations on them. Look up Asiya bibi case or Salman Taseer who was killed for opposition to blasphemy law.
There is a strong theological basis in Islam for stopping all criticism. Look up the story of Asma Bint Marwan. There in lies your problem.
