This is an unreasonable demand to make. It is impossible to adequately explore the topic of opportunities (or lack thereof) for minority authors without addressing larger social questions around privilege and marginalization and how to tackle them.
If you are unwilling to allow such a discussion to take place, you ought to close the thread.
I appreciate your passion for this subject, but to suggest that if we don't discuss all of the larger issues then we shouldn't discuss this specific one –– defeats your purpose, no?
An alternative option would be to continue the conversation on this issue and you could start a different thread with the broader conversation you want. Instead of shutting down this thread, we'd have two!