We seem to mostly agree that diversity is important, and having employees from different background help bring different ideas and solutions to the table, react with more agility on unforeseen situations.
On a fundamental level, applying the same vision and forcing the same values and rituals on everyone looks to me at odds with what diversity is supposed to bring.
As an aside, if a company has a credit card processing division and mini-game producing divisions, I'd see a clear case for them to not have the same values nor the same priorities, and in the end the same culture. That's what I also felt reading accounts from UX designers at Google in the early days, when they seemed to be crushed by the 100% data driven culture from which they tried to carve a small niche.