It's the fact that this is a thing to even have to ban that's the worst part. Humanity just hits lows like this in its cultural practices sometimes, and the best we can do is work to ensure that nobody else suffers FGM like so many others have.
This issue was discussed in Half the Sky, the book Celeste and I did for our presentation. The authors specified that in order to end cultural practices like this, aid groups need to work with local people rather than through the government. I'm glad to see the British taking this advice, they mentioned the nonprofit Tostan in the article, which was praised in the book for using the right approach to ending this horrific practice.