As for what the writer mentioned about the disadvantages of immoderation and excessiveness, it is quite right.
Undoubtedly, Islamic Shari`ah warns against extremism in religion, and ordained the call for the way of truth with wisdom, fair preaching, and argument in a way that is better. However, it has not overlooked harshness and strictness in their due place where leniency and argument in a way that is better are of no avail, as Allah (Exalted be He) says, O Prophet (Muhammad ﺻﻠﻰ ﺍﷲ ﻋﻠﻴﻪ ﻭﺳﻠﻢ)! Strive hard against the disbelievers and the hypocrites, and be harsh against them He (Exalted be He) also says, O you who believe! Fight those of the disbelievers who are close to you, and let them find harshness in you; and know that Allâh is with those who are AlMuttaqûn (the pious See V.2:2). Allah (Glorified be He) also says: And argue not with the people of the Scripture (Jews and Christians), unless it be in (a way) that is better (with good words and in good manner, inviting them to Islâmic Monotheism with His Verses), except with such of them as do wrong Thus, He made it lawful for His Believing slaves to be harsh against the disbelievers and hypocrites when Da`wah with wisdom and lenience fails to affect them.
Although the Ayahs (Qur'anic verses) are about dealing with disbelievers and hypocrites, they indicate that the Shari`ah admits leniency in its due place when it is hoped to bear fruit. Yet, if it brings about no benefit and people persist in injustice, disbelief, or transgression to the disregard of preaching and advice, they should be held back and treated harshly. Hence, they should be subjected to the due measures of Hudud (ordained punishment for violating Allah's Law), Ta`zir (discretionary punishment), threat, or reprimand until they observe the limits and are deterred from their assumed falsehood.
The (concerned) writer and other writers should not forget what is mentioned in this regard of religious texts and occurrences from the time the Prophet (peace be upon him) was sent until the present time.
In this context, how eloquent are the words of the poet who said,
Unanswered, the Prophet remained to preach in Makkah in a mild manner and a soft speech. With a sword unsheathed, his words reached And stubborn hearts humbly surrendered