Jinraya: You've got a good 5 minute idea, now expand on it. Where will it be located? What type of enemies will be there? What bosses. What relevant reason (lore-wise) would it have to run it? Where will you place chests if randomly generated? How about the loot tables for the chests? What special ideas will you try that haven't been done yet, besides random elements? Any special mechanics for the boss fights? How will you balance it for casters? How will you balance it for melee?

I'm not shooting your idea down at all. I like it actually. But I said all that to show that it does take more than 5 minutes to come up with an idea for an instance. You may dislike what exists now, but don't think there wasn't work or planning that went into it.