Diversity IS, not 'was.' It was not diverse when founded. Please try to read correctly so you can actually respond rationally.
And diversity is not a myth, it is a proven biological concept that can also be applied to societies.
Diversity is about the variety in genetic material that gives a species the ability to meet a wide number of environmental challenges by having individuals that can adapt and succeed. The more variety, the more likely it is there will be individuals able to overcome the challenge.
That applies in a society as well, and leads to innovation, strength in work, sports, war, health, a wider variety of talents and skills to meet challenges, ability to resist disease, etc etc etc.
LOL, a 'myth!'