This doesn't exactly seem like a groundbreaking, world-changing suggestion.

It's not meant to be. The main benefit behind this idea? It requires nearly zero dev time. All that's required is to create a player interface for a party leader to fully control what Level and Item Level his party is synced down to. Throw in an option to disable the Echo for premade parties as well. Once you've put in the dev time to create that, from that point onward, the players create challenges for themselves. Obviously it's not as interesting as new content, but the point is that it doesn't take the place of new content, it simply supplements the game during the lulls between patches.