Just in case that applied to me:
Actually, I visited the NA community every chance I had. Not as much as I would like (b/c I couldn't afford it), but took in a lot of the culture from research etc (my interest dates to before I knew how much I was, prior to my parents' seperation I thought it was about 1/10th).
Also, I'm not 1/16th, I am also 1/4 (since the other side of the family tree is ambiguous, I know it is between 20-30%, so I will stick with the median, even though I gave a conservative estimate earlier). I know you can qualify with as little as 1/16th, but I would never do that and when I thought I was 1/8th I didn't include it on my app.
Even though I didn't face challenges specifially as a NA, anything I faced as a member of minority group at home made me realize more about hatred than I ever would have living on the mainland (where it is still not clear I am NA). I faced poverty, hatred, and abuse to an extent that is not representative solely in my race. Growing up in Hawaii also gave me a unique appreciation for being MULTI-racial. Practically everyone at home is mixed and even those kids who were like 5% Hawaiian would claim that part of their heritage. So, basically, I identify far more with minority groups than I do with white people because, until I was 18, I never had the experience of being in a majority.
I asked to gain experience from people in the community who may have faced the same dilemma at some point. I have always had to go through these processes by myself because no one in my family has had experience like this (applying to college, much less grad or prof. school) and I was looking for support.
Going along the same point I think you were trying to make, you should know someone's full experience before bashing them or their decisions.