Prophet Muhammad(PBUH) married Hazrat Aisha(RA) when she was only 9 years old and he was 53. He in fact proposed her when she was only 6.

This sounds strange that the most genius person in the world would marry a 9 year old girl? For what? This would mean that a divine decree was involved here and that God had special place for Aisha(RA). But even that is doubtful. Hazrat Aisha(RA) has been a main cause of the rift in Islam i.e. Sunni Version and Shia Version. Shia Muslim do not really favor Aisha(RA) in a number of ways

• That she propelled her father into caliph-hood when the Prophet died;
• She fought against Hazrat Ali in battle of Camel. (Having a sound mind, I think it was wrong on her part to get involved in such war, especially that she was defeated);
• The marriage of Aisha(RA) to the Prophet was not the happiest marriage in the world. Even the Quran talked about their divorce 33:28-29;
• Her own right as a little girl was violated by having such early marriage;
• I have heard her first menses came when she was 14. This falsify the claim that she was really an adult at the time of marriage.

O Prophet, say to your wives, "If you should desire the worldly life and its adornment, then come, I will provide for you and give you a gracious release. But if you should desire Allah and His Messenger and the home of the Hereafter - then indeed, Allah has prepared for the doers of good among you a great reward." [33:28-29]

So the question is, why did the Prophet marry a 9 year old girl when potentially it brought no good to Islam. Yes there are huge number of hadiths related to her but they are related in a chain and majority of them are not accepted by Shia Muslim (and hence my question). Why did the Prophet marry a 9 year old girl?

If this was divine decree, wasn't it terribly wrong one?

Disclaimer:I am Sunni Muslim and this question is I no way intended to defame Aisha(RA). She is Ammul-Momimin. My question is really about God, and how he makes decision, which can be potentially wrong. Also note that I will accept Sunni Islam view answer, although Shia answers are highly encouraged.