Worse than Ayesha's age

What I find much worse than Aisha's age is the fact that Mohamad didn't allow any of his wives to remarry after he died. A few were in their 20s and Ayesha was only 18? What if they wanted to have kids? What if they wanted a lifelong companion? I just can't comprehend how people can think he was a good guy when he did things like this.