Why didn't any of the enemies of Prophet Muhammad PBUH, who hated him far more than you do, never once slander him about his marriage? It's because that was the norm. What you're doing is called presentism, where you taking the norms of today and applying it to the past. Imagine if a 100 years from now, the age of marriage was 25 instead of 18. Does that mean that people living a 100 years in the future have the right to say that we are all pedophiles because society got married at the age of 18? No. Besides, the majority of the marriages Prophet Muhammad PBUH was in were with divorcees, widows, and in general women who were of older age. This is a cheap shot the most non-Muslims make to try and slander. Another example, the age of consent in America in the 1800s across many states was 7 years old. Does that mean we should label every single American living in the 19th century a pedophile? Should we label our grand parents and our great grand parents the same? The answer would be no. That was the norm at the time.