I know exactly what you mean. I have been to the Memorial eight times. Everytime we pulled in at Pearl Harbor, I went to pay my respects to my "brothers" who still lie entombed on her. The last time I was there the Memorial was crowded with Japs and to see them smiling and laughing in that sacred place provoked anger in me. It would be like me laughing at a place like Hiroshima. They smile and laugh real good until you remind them of where the Atomic Bombs were field tested at.
Tourists... they don't always know better.
I have been to sacred shrines in Hiroshima, and I have seen many Americans wearing touristy clothing and laughing and chewing gum. We are just as guilty.