I don’t think anyone thinks it’s weak. I think it’s expensive, and I think keeping Orpal alive long enough to get him to maxband and keep him there and be able to afford D&D is kinda hard, and so it scares a lot of people away from attempting it.
Death Rites, on the other hand, one could argue is weak in a way similar to Maximum Anarchy.
MA is only useful if you have a decent hand after you play it, and you’ll only be able to play it if you’ve managed to mostly control the board (keeping max Zane alive). Which means you don’t really need to play it, because you probably already have max Zane facing an enemy’s empty board.
Death Rites allows you to have your weenies take out much bigger opponents, or turns their trades into 2-for-ones. But to do that you really have had to maintain a large board of weenies and keep max Garth alive. If you can do that, do you really need the ult? It’s situational, and if you end up with a surprisingly empty board, it’s useless.