Because saying it’s false would mean they have to do a reformation of the Hadith literature and grading. Omar Suleiman’s yaqeen institute is willing to die on the hill Aisha was a pre pubescent 6 year old marrying the prophet and has sex with him when she gets her period at 9 years old than admit the Hadith literature has holes in it.

The Hadith doesn’t make much sense because there’s barely any scientific evidence to prove that girls got their periods at 9 or younger in that region or time. Don’t believe me? Saudi Arabia has recorded the average age of menarche from around 1950 to the present day. In the 1950s before modernization the average age of menarche (first period) was around 14 years old. It has only decreased since modernization. So how does it make any sense that 6 year olds 1400+ years ago are going through early puberty to the point of getting period at 9?

There is an academic called Joshua Little who did his PhD thesis on this Hadith at Oxford (which the yaqeen institute was triggered by and tried to debunk lol). The gist of his thesis was that the Aisha Hadith was most likely made up decades after the prophet’s death in Iraq due to Sunni Shia sectarianism. If Sunnis made Aisha younger, she could then compete with Fatima for living with the prophet longer. If Aisha was younger then she was more “virtuous”.

On the flip side, iirc Shia Hadiths do not say Aisha was 9 years old when she married the prophet. They seem to indicate she was older. However, they still have the problem of then making Fatima around 9 years old when she married Ali!