I don't recall anyone stating NT was going to prevent injuries, and "no", NT won't be the magic to prevent stupidity. What it will provide is an option for many AS athletes that have chronic injuries, are blocking, are on the cusp of 5 tumbling, and many extremely talented stunters that end up leaving AS. As the level 5 tumbling requirement bar continues to rise, so do the ACL/ MCL/ meniscus tears, dislocations, sprains, and breaks. The human body, especially a child's, has limits. It's an option, not the end all or answer to everything.
The only debate I find legitimate is whether or not it deserves to be at World's. IMO, much like skiing in the Olympics (alpine, cross country, freestyle, nordic combined, jumping), there can be variations of a sport that medal that are equally impressive. With that said, I'm sure there is probably a skiing debate on what category is the most elite or well rounded.