I'd agree that "more rulz" isn't a solution. If it was, games like RIFTS would be the best games around. Or Role Master. Or GURPS. Obviously that's not true.
However, I will say that having clear, easily applicable rules with clear intent and transparency are FAR preferable and a huge aid to creating better DM's and GM's. When you can point to a rule and say, "We do it this way because we want this and that result. This and that result will help because this and that result feed into these other things."
We don't make better DM's by throwing them in the deep end and hoping they don't drown.
One thing where the old Moldvay Basic set absolutely glowed about was that it laid out, very clearly, very concisely how to create an adventure. None of this world building nonsense, at least, not for the neophyte DM who is just getting started. Just, "Here is a town, don't worry too much about the town right now because the town isn't where the interesting stuff is. Here is the dungeon, that's near(ish) the town. Here's how you make an interesting dungeon that will entertain and engage your players. Once you have mastered these basic steps, then you can move on to the Expert set and we'll expand things."
The DUngeon Master's Guide, outside of maybe the 4e DMG, for every edition has been absolutely crap at teaching DM's how to run a game.