All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
Imaam As-Suyooti mentioned this specious argument and a refutation of it in his book Al-Itqaan. He said: "Al-Naththaam (a Mu'tazilite theologian) claimed that the miracle of the Quran was achieved by As-Sarfah, i.e. by Allaah preventing the Arabs from imitating it, and stopping them from using their minds in producing a rival to it (known as the Sarfah theory), and that they were capable of imitating it but an external factor prevented them; so it became like any other miracle.
This statement is defective (and self-defeating) as evidenced by the verse that reads (what means): {Say, "If mankind and the jinn gathered in order to produce the like of this Quran, they could not produce the like of it, even if they were to each other assistants."} [Quran 17:88] This verse indicates their failure with the subsistence of their ability; had they been deprived of this ability, there would have been no point in them gathering! It would have been the same as a gathering of dead people (attempting to do something); verily the inability of the dead is not worthy of celebration or remark. Moreover, the unmatchable quality of the Quran's extraordinary eloquence and unique perfection have been established by the scholarly consensus; how then could it be claimed that the Quran is not miraculous and that it is Allaah Who prevented them from producing a rival to it!
In addition, the implication of the Sarfah theory is that the miraculous nature of the Quran would end with the end of the time of the challenge. This would constitute a violation of the consensus of the Muslim community that the Quran is the Prophet's everlasting miracle.
The Qaadhi Abu Bakr said, 'In refutation of the Sarfah theory, if it is claimed that they were able to produce the like of the Quran but Allaah prevented them, this would have meant that the Quran is not of a miraculous nature and that the miracle was achieved by prevention. Accordingly, this would have meant that the Quran is not actually of any superior quality compared to human speech." [End of quote]
Claiming that "a lot of scholars" agree with this is a clear exaggeration; if you compared this opinion to that of Az-Zarqaani in his book Manaahil Al-‘Irfaan, you would easily recognize this exaggeration. He wrote, "The view pertaining to the Sarfah theory is attributed to the Sunni Abu Is-haaq Al-Isfaraayeeni, the Mu‘tazilite Al-Naththaam, and the Shiite Al-Murtadha."
We advise you to refer to Manaahil Al-‘Irfaan by Az-Zarqaani where he has refuted this specious argument at length.
Allaah Knows best.