You don't understand merged mining because you don't understand why mining exists. The point of it is to secure the coin, not make money on a P & D and move onto the next shitcoin.
+1 (couldn't say it better)
I'ts not that I don't understand merged mining I'm just pointing out that there isn't any appeal
in it for miners. For the coin to be secure it has to appeal to a large number of miners or the principals
need to supply enough hash themselves. The merged coins have so little value they can't make it on their
own so they hook up with a larger coin and feed on its appeal.