Apostate prophet finds a good reason for piecemeal revelations; gradual societal reform?

In answer to the video "Who (Really) Wrote The Quran?"

The Quran relates how the prophet's opponents among the pagans and the People of the Book did everything to make him compromise his revealed principles with theirs, forge verses or deliberately corrupt them but the message was divinely protected from the interference of the evil ones -men and jinn- from its descent from heaven all the way to its uttering by the prophet who was repeatedly warned 2:145,10:37,42:15 and never allowed to yield one bit to them despite the hardships he and his followers suffered.

Like the prophets of old, who despite the pressure to alter the divine messages and make them more appealing he answered

2:120,10:15,13:37,17:75,68:9,69:44-7,40:66"Say: I am forbidden to serve those whom you call upon besides Allah when clear arguments have come to me from my Lord, and I am commanded that I should submit to the Lord of the worlds".

As reflected is sura qalam, which is among the earliest Meccan suras, pressure was already being imposed on the prophet at the onset of his mission to change and compromise his message. It is to be noted, when the Noble Book unapologeticaly warns its messenger in the context of temptation to yield to his opponents, these frequently seen conditional statements do not mean that the prophet was actually tempted in doing so.

There are many implicit meanings to these warnings, including that regarding the obligation to abide by the divine law/sharia, there is no difference between a prophet and a regular believer.

The second thing is that, seeing that the prophet is warned, how much more should they be careful of their responsibilities in upholding the principles of this revelation. And finally, seeing and hearing that the messenger is in no position to change anything in Allah's ordinances, the enemies should know that it would be fruitless to even think of approaching him with such objective.

When the prophet Micaiah the son of Imlah was under the same kind of pressure, he answered, knowing the dangerous repercussions of refusing to yield to the rejecters

1Kings22:14"As the Lord lives, for what the Lord will say to me, that will I speak".

The prophet Isaiah was equally warned not to yield to the disbelievers' requests Isa8:11 who, unhappy with his strong warnings and admonitions, would openly demand that he should forsake the straight path, the true God and give them false prophecies

Isa30:10-11"You shall not prophesy for us true things. Speak to us with smooth talk; prophesy mockery". 

The prophet's opponents practiced deception upon him, and tempted him with greed, held out threats, and raised a storm of false propaganda against him, and persecuted him and applied economic pressure and social boycott against him. Yet the prophet did not compromise an iota of what was revealed to him, even in the direst Meccan period. Although he did experience fear at the consequences, never did he withhold a word that needed to be uttered in the face of his opponents, so as to soften their stance. Even when his uncle and protector Abu Talib was pressured by a Meccan delegation to withdraw his tribal protection of Muhammad and the Muslims, he firmly replied: 

"0 my uncle, if they placed the sun in my right hand and the moon in my left hand to cause me to renounce my task, verily I would not desist therefrom until Allah made manifest His cause or I perished in the attempt". 

The prophet then turned to depart until Abu Talib called him back 

"Say whatever you please; for by the Lord I shall not desert you ever". 

It is to be stressed that the prophet took this stance when his uncle, his last resort, seemed on the verge of letting him down. This attitude, besides the established reputation he had as a man of great integrity by his friends and foes, before and after the revelation, confirm the testimony of God Himself about His chosen one 

68:4"And indeed, you are of a great moral character".

The Quran also presents situations where the prophet is showing fear in communicating certain revelations to his people 5:67,33:37 fearing their reaction, judgements or tauntings but the Quran would compel him to keep transmitting what he is receiving, not to ever

11:12"give up part of what is revealed to you"

showing how he wasnt acting according to his whims

2:120"If you (Muhammad) give in to their whims and desires despite the knowledge that has reached you, you will have no protector or helper against Allah".

So in the second part of the verse 25:32, God outlines some of the major benefits of this gradual process of revelation

"Thus that We may strengthen thereby your heart; and We have recited it in (clear) reciting".

This concise statement implies a deep impression on the minds, causing a smooth acceptance of its Laws. It would not be possible if all the Commandments and the whole system of life had been sent down all at once. The process of diverting a people from the social norms which they are accustomed to and which have nurtured their ideas and ideals, to make them question and ackowledge the errors of the systems which they grew up believing in, emulating generations of their ancestors, to make them assimilate the laws and wisdom of the Book which was going against their ancient practices, the process had to be gradual

17:106"And it is a Quran which We have revealed in portions so that you may read it to the people by slow degrees, and We have revealed it, revealing in portions"  

28:51"We have caused this word [of Ours] to reach mankind step by step, so that they might [learn to] keep it in mind".

Since the beginning, the prophet, despite his fear and reluctance is assured that he will be led and guided every step of the way, in his words and deeds, when the time is appropriate until his momentous mission is complete.
The parallel is made with all natural phenomena as they pass through various gradual stages before reaching the culminating point 87:1-18.