Wow.
First off, your position is waaaaaay too extreme. Nobody - certainly not me - called them "money-grubbing greedy jerks," nor do they want to "take all your money." But they do want to make a profit, like any other business. And the trouble with ongoing patches, DLC etc. is that those add to the price tag. Skimming a commission off the top of the RMAH does not.
Second, I couldn't disagree more with everything you wrote above. There is simply no way they could sell gameplay items directly to players without turning it into the absolute worst free-to-play MMO on the planet. It has nothing to do with them caring more about your fun than making money, and everything to do with that being a godawful business model. Once you legitimize selling power, the long-term in-game economy is ruined; players go from wanting to drop a few extra dollars on the AH, to feeling like they have to, which removes any notion of fairness from the game. You then lose entire demographics of players (including the crucial 14-18 group that simply don't make the kind of money to be blowing on digital items, yet who have the time to put in to theorycrafting builds/updating wikis/making how-to gameplay videos etc.) Furthermore, players lose the ability to make money themselves from being successful at the AH. If everyone can buy X item directly from blizzard, that is effectively a price ceiling - nobody is going to pay more for X from a 3rd-party when Blizzard's supply is infinite. Restricting markets in this way serves no purpose except to create a deadweight loss.
Making a commission off the player-run economy is far more sustainable and will make them a ton more money in the long run. I'm not saying that Blizzard doesn't care about supporting the base, I'm saying that they are savvy enough to know that the long-term dollar is far more attractive than the short-term one. If you for a moment think that selling items directly is more financially feasible than simply getting a commission, your knowledge of e-commerce (and commerce in general) needs a lot of work.