To each their kind of understanding. Two-spirit, like I say, was just a term created at a point to encompass those who were lesbian, gay, bisexual, transgender or intersex. That's where that term was created.
Why? I wasn't there. I don't know the discussion that happened when the term “two-spirit” was created and why “spirit” was actually put into that. That's not something that I've learned yet in my brief five years of coming to understand myself and of identifying as two-spirit.
I have still much learning to come.