Obviously the article pertains specifically to the UK publishing industry, but don't think for a second the situation is any different here.
There have been many publishing houses I've worked at where I was the ONLY minority. Yes, that's right--the only one. The last publishing house I worked at, a very very large one, employed some minorities, but mostly in office support positions. There were some minorities in the art ghetto, mostly Asian. The one African-American editorial assistant left after four years without getting a promotion. In my experience, she was among the most efficient and pleasant people I dealt with at this company. I don't know why she was never promoted.
It was at this publishing company that I was denied a request to sit on the "diversity" committee. Yes, that's right, one of only 2 Hispanics not in an office support role was told that there was no room for her. Sorry! We're filled up with white folk from the Ivy League! Too bad for you! How did they hope to diversify the company when they couldn't even diversify their committee?