They need to shake up dungeons a bit but as people said. Multiple paths are not a good idea, now I do think it's a good idea for leveling dungeons because extra mobs to kill for exp but for lv80? Mmmm it needs an incentive.

Now...if they added treasure chest that had stuff worth while getting then.
Like say the off beaten two paths that had a chance to have a chest that had 5x matera in it or rare crafting mats for a minion or mount or glamour crafting mat.
I think that alone would make dungeons active as people would be farming it.

Also make it so you can't roll on it until the dungeon is done so people don't just poof.