I believe you can mess a dog up using just about any method, including positive ones. However, you can definitely do more damage faster by incorrect use of aversives, so if you make that choice, you had better know what you are doing!
As mentioned, TV lends itself to "instant fixes", and it would make for pretty boring TV watching the careful steps a positive trainer would go through to deal with a particularly difficult dog. Editing won't work, as people will smell a rat and think you did something off camera to improve the dog's behaviour. I'm not defending CM here, only explaining why he is popular.
Personally I don't rule out aversives, but they are not the correct tool for many (most?) dogs. For very specific applications, done correctly, they have the virtue of results that are much more resistant to extinction than those gained by positive methods, and therein lies both their value and their potential for lasting harm.
I found Pamela Reid's, book, "EXCEL-ERATED LEARNING", particularly illuminating on this point.