From the article:

"This wasn't a case of that awkwardness because someone doesn't know what to say. He knew I was there. I just wasn't worthy of his attention. I stepped back, put my full wine glass down on the nearest table, and walked out of the building into the November wind. "

A lot of these comments are focusing on "not fitting in".  This is about more than "not fitting in".   This is about being subjected to people who deny someone exists as a human being.   That's never acceptable. 

Although I'm not black, I can 100% relate to a lot of what is in this article.