That's the cultural divide for you. Pretty much everyone teaching finance could make more dough working in private industry. And being a practitioner in private industry is also fun and deeply fulfilling in its own way.
As for the quality of who teaches and who works in industry, I don't think the quality is higher in private industry. Academia more than holds its own when it comes to attracting the best. And of course there are plenty who go back and forth between academia and industry, which is generally good for the field.