I have often heard it said there are 84,000 gateways to the Dharma (Buddha's teachings). Buddha presented the same underlying philosophy with different techniques and methods according to the predispositions of the students.
With so many different schools it is almost impossible for Buddhists not to accept and respect diversity. Historically speaking the various schools of Buddhism simply don't persecute one another. There have been a few local exceptions, but history has shown few cases were the schools went to war against each other.
There is Theravada Buddhism, Mahayana schools, Zen Buddhism, Pure Land Buddhism, Yogacara Buddhism and Vajrayana Buddhism but in the end it is all Buddhism. You have your the Vinaya School, the Esoteric School, the Chan School, and the Pure Land School and still it all is Buddhism.
Wherever Buddhism has traveled it has taken on the trappings and tastes of its new home, but in the end despite the conviction that they are right and the other schools wrong, mostly they have just ignored each other or upon occasion traded a few insults. And almost without exception, there is one glaring exception I won’t name; the core message has remained unchanged.
The Buddhism we practice and the first generations of teachers that have brought Buddhism to American have done their best to hold on to the ceremonies, the costumes and the traditions developed in their countries. But looking back we can see that Buddhism has always adapted itself to its surroundings.
The Americanization of Zen and Buddhism is inevitable. I am sure in the end all the past teachers who traveled to far away lands, simply laughed and made a comment about the inevitability of change when they saw their teachings putting on new clothing. There of course will no more be “one” American Zen than there is one type of Chinese or Japanese Buddhism.
I wish I could be around in a hundred years to see what real American Zen looks, tastes and smells like.