I'm giving this episode an automatic 10. I did enjoy it, it had some hilarious parts, like Cartman and his ass burgers, but what got me was the underlying and message, and the blunt and very typical South Park way of conveying it. It was sad and pessimistic, but very very real. And it's such a universal and obvious issue, that people don't really stop to think about. In fact it's even the oldest philosophical dilemma. But it was brave too, and that's what I love most about South Park.
Basically, everything is in fact shit. Metaphorically. All our actions, creations, activities, beliefs, goals, and perceptions are products of a mind ill-conditioned by a toxic society. i.e. The intensified amassing of the world's populations into squashed up, dense freak shows for cities has bread generations of superficial, money-grubbing bullshit. All designed to lie and cheat you into liking and buying. And everyone is a part of it. Most people don't realize it, others who do just try and accept it and coexist, like Stan.
This is a common theme. It was used in the Matrix, and South Park's creators parodied that film cause it's the most recognizable interpretation of Plato's Cave Allegory. Plato's story goes that in the cave, people are sitting and watching a wall onto which shadows are being projected. They people see them and take them for granted, believing them to be real figures. All the while a fire burns behind them, and someone else (whoever else and for whatever selfish reason) is projecting those images, and deceiving the ordinary people. Plato held that the philosopher's role was to free the metaphorical cave dwellers and show them reality. Of course this personal sense of obligation might be a rare find, especially in todays overly saturated world where it's very easy to get lost.
So in Ass Burgers, Stan starts to mature, and turns out to be clever enough to recognize the bullshit. Of course in the show it's shown as actual shit for humor value. Naturally it gets him down. In the meantime bullshit continues: Steamy Ray Vaughan, Aspyrger's caused by vaccinations, and ass burgers. Stan probably learns three things: There are others like him, i.e. he's not crazy or alone, the shit will continue, booze helps.
The duck is replaced by O'bama implying that some things get better, and the final message is that the world is shit, you will lose the wonder and curiosity of youth, but that's life. It won't always be easy, hell for some it can be depressing and even worse, but you endure.
Well that's how I saw the episode. It really spoke to me and this is my personal take. I understand that others my see it differently.
Now the real question is how to we get rid of all the shit and make Stan happy again?
As a side note to hpfan, I wanted to say that yeah, the end of South Park as we know it and Stan drinking is definitely depressing, but just like the point I think the creators were making, it was real. A blunt heavy episode, and fearless as they always are. It was actual art, instead of watered down art (art with some BS mixed in) made familiar just to please the fans. If you're a real fan, applaud them for making a stellar piece of work. I will admit, this line of action could ruin South Park if they continue it; it would be VERY hard to maintain Stan's problem as dramatically as this in their world day to day. Either this gets watered down or disappears, or they totally revamp the show, or they near the end. Either way I'm glad about the episode so independently I give it a 10.