No argument from me - but how many people are using it? Just from watching SO for a few days it seems that nearly all of the people having trouble with their code (tagged 'mysql' and 'php') are using the old methods. Almost no one is using PDO for their projects (in that limited demographic, at least).

MDW is just to lower the barrier to entry a little bit for people like that. Easy to use, easy to understand, and thanks to the helper pattern, the interface won't change if something better than PDO comes along.