Well this argument is very easy to debunk, all we have to do is quote an authentic hadith which reports a very interesting incident that occurred between the pagans the prophet Muhammad himself, the report is as follows:
Yazid b. Ziyad from Muhammad b. Ka’b al-Qurazi told me that he was told that Utba b. Rabi’a, who was the chief, said one day while he was sitting in the Quraysh assembly and the apostle was sitting in the mosque by himself, Why should I not go to Muhammad and make some proposals to him which if he accepts in part, we will give him whatever he wants, and he will leave us in peace?’ This happened when Hamza had accepted Islam and they saw that the prophet’s followers were increasing and multiplying. They thought it was a good idea, and Utba went and sat by the prophet and said, O my nephew, you are one of us as you know, of the noblest of the tribe and hold a worthy position in ancestry. You have come to your people with an important matter, dividing the community thereby and ridiculing their customs, and you have insulted their gods and their religion, and declared that their forefathers were unbelievers, so listen to me and I will make some suggestions, and perhaps you will be able to accept one of them.’ The apostle agreed, and he went on, If what you want is money, we will gather for you out of our property so that you may be the richest of us; if you want honour, we will make you our chief so that no one can decide anything apart from you; if you want sovereignty, we will make you king, and if this ghost which comes to you, which you see, is such that you cannot get rid of him, we will find a physician for you, and exhaust our means in getting you cured of it’, or words to that effect. The apostle listened patiently, and then said: Now listen to me, In the Name of God, the compassionate and merciful, H.M., a revelation from the compassionate, the merciful, a book whose verses are expounded as an Arabic Quran for a people who understand, as an announcement and warning, though most of them turn aside not listening and say, Our hearts are veiled from that to which you invite us.”” Then the apostle continued to recite it to him. When Utba heard it from him, he listened attentively, putting his hands behind his back and leaning on them as he listened. Then the prophet ended at the prostration and prostrated himself, and said, You have heard what you have heard, Abu Al Walid; the rest remains with you.’ When Utba returned to his companions they noticed that his expression had completely altered, and they asked him what happened. He said that he had heard words such as he had never heard before, which were neither poetry, spells, nor witchcraft. Take my advice and do as I do, leave this man entirely alone for, by God, the words which I have heard will be blazed abroad. If (other) Arabs kill him, others will have rid you of him; if he gets the better of the Arabs, his sovereignty will be your sovereignty, his power your power, and you will be prosperous through him.’ They said, He has bewitched you with his tongue.’ To which he answered, You have my opinion, you must do what you think fit.’ (Alfred, Guillaume. The Life of Muhammad, A Translation of Ibn Ishaq’s Sirat Rasu Allah. Oxford University press, 2002. PP. 131-132)
So notice what the pagans did, they sent a representative to try and negotiate with the prophet Muhammad, they offered him power, money, and anything he wanted! If the Prophet Muhammad’s goal was for all of these things then why didn’t he accept it, it was mission accomplished if we are to believe the critics argument.
The prophet Muhammad completely rejected the offer, and he rejected it in the most beautiful manner, by reciting the Quran, to show them that this is the truth, and the truth cannot be compromised for anything, and that it isn’t about money or power, it’s about salvation and bringing people back to the straight path of God.
So no, the prophet Muhammad was not out for money, power, or to become a king, if he was, then he would have accepted this offer, rather he rejected it and went through so much trouble, hardship, pain, and all for the truth of Islam.
And Allah Knows Best!