MMA, now and back then, is a business. Techniques like eye-gouging, small joint manipulation, etc. would put athletes out of subsequent fights for long periods

MMA, now and back then, is a business. Techniques like eye-gouging, small joint manipulation, etc. would put athletes out of subsequent fights for long periods of time or even permanently...not a good business model for anyone. With other types of submissions there is usually plenty of time to tap out to avoid permanent injury. So AFAIK there's no moral imperative at play here. I've also never witnessed a broken neck in my ten plus years of watching MMA. I'm sure it's happened, but most likely as an unfortunate accident and not intentionally.