It lasts past day one, people run those dungeons every day for tomes, if you make all future dungeons midcore then what kind of new content would casuals get? I'm not sure what you mean by "organized content", if The Burn had mechanics with a high penalty rate then that's no different than Suzaku EX or the first savages, you don't need constant party communication to do Suzaku EX, just bare minimum such as assigning spots.