I don't think this is related to what I mentioned. I'm truly surprised that this subject is not relevant to you or, treated like if I was joking. I am just saying the term has indeed the connotation of "what is black is wrong". I failed in providing an article to corroborate with my position. I will try to find something.
The term "black", etimologicaly speaking, is racist and should not be used. Japanese culture seems also to be racist, so not a surprise. Instead of "black companies", kindly use "evil companies" instead.