The "Hollywood cares only about making money" argument is the same as the "Southern diner cares only about making money" argument. Diner owners said desegregating their eateries would drive away white customers. Studios say desegregating their movies would drive away white customers. Same reasoning, same "logic," same underlying racism.
Making money isn't a valid excuse for immoral behavior such as racial discrimination. Discrimination is difficult to prove, but if we could prove it, it would be against the law. Hollywood shouldn't get a free pass just because we can't prove beyond a reasonable doubt that it discriminates illegally.
I could go into a lot of detail justifying this argument, and already have. The bottom line is this: a business's employees and customers should reflect the surrounding population's demographics. Any deviance from this is reason to suspect racism.
The US population as a whole is about 30% percent minority. Nationwide products such as movies should reflect the nation's demographics. Movies don't and that's a problem.
For more on the subject, see Patel's Struggle Shows Hollywood's Racism and Americans Refuse to Acknowledge Prejudice.
Below: "We're just giving our customers what they want!"