Balancing 9/11’s horror

Why is balance so important in a facility like the 9/11 Memorial and Museum?

Two developments in the 9/11 Memorial and Museum in New York give cause for deep concern.
One is that Arabic, the fourth most-spoken language in the world, is not among the 10 languages chosen for literature explaining the 9/11 Memorial. The other is that the museum has no mention of the long peaceful Arab history of that part of lower Manhattan, known as Little Syria.
The authorities deny there is a deliberate marginalisation, saying Arabic is the 25th most-spoken language of actual visitors and that the inclusion of Little Syria was suggested too late to be included.
That misses the point. Prejudice relies on homogenisation to spread its evil message: if some members of a racial, religious or political group do a bad thing, then the impression is that everyone from that group must think exactly the same way.
This is flawed thinking and it's also dangerous, which is why balance is so important in a facility like the 9/11 Memorial and Museum.