First, that only works for potential biases you already know about and can anticipate, or can spot in the output. If the result is an egregious ripoff or an artist you’ve never heard of, or is the likeness of a model or actor you’re not aware of, how would you know?
Second, it doesn’t create the kind of originality we want. It just limits the kind of unoriginality we are getting.
How useful is an image generator that, when asked to generate an image of an archaeologist in a hat, gives you Harrison Ford every time?
Clearly that’s not what we want from tools like this, even just as tools.