Yeah, and some of my ancestors were probably slaves, had slaves, or thought slavery was OK. Does that mean slavery is OK? Your logic is poor. You're arguing that because pedophilia was culturally accepted in Muhammed's time, it wasn't wrong. The same logic could be used to justify slavery of people based on race among many other atrocities.
I'm not sure anyone is arguing that paedophilia was culturally acceptable - ever. Marrying at a young age doesn't necessarily then imply that sexual relationships happened at such young ages. And neither does a very young age for marriage or no such limits. All it seems to say is that children in the past were just seen as the properties of their parents, to do with as they wished, and had little say in such matters. I've quoted elsewhere, when the age of consent was just 12 in the UK, very few (less than 2% of 1000 cases recorded) married at age 16 or younger - this was around 1600, when Shakespeare was alive. I think the early age of marriages, few that they were, can be understood in this context, and it hardly then says anything at all about paedophilia. I doubt we know enough about Muhammed and Aisha to comment much more.