He acquired a wide reputation for his critical attitude towards political and religious institutions and his willingness to cover controversial topics in a rational way.
His novel Walimah li A'ashab al-Bahr, (A Feast for the Seaweeds), was banned in several Arab countries, and even resulted in a belated angry reaction from the clerics of Al-Azhar University upon reprinting in Egypt in the year 2000.
Al-Azhar University students staged huge protests against the novel, that eventually led to its confiscation.
"[4][5] In a 2019 interview for the magazine The Common, Hisham Bustani wrote about Haidar: "He has kept a fierce, critical distance from all sides: the dictatorship of the ruling regime in his country of Syria; the dictatorship of public taste and ‘conventions;’ the oppression of dogmatic ideology and the ruling party; the tyranny of power derived from religion.
In order to do so, we need to re-read it in a scientific, historical, secular, objective way - to de-holify it, re-interpret its texts, and critique it with openness, with the ruthless scalpel of a surgeon and without the restriction of “holiness.” We need to approach it away from the dichotomy of the sacred and the profane, and away from irrational and superstitious attitudes.