I am not happy.
I will be discussing my brother's behavior with him.
He doesn't really game outside of his circle of friends. Most of these guys like to create anti-hero loner types, the classic Chaotic "Neutral" sort of character, and run amok in whatever game they happen to be playing in. Typically they will be hanging out, someone will suggest a game idea, they will all make characters, play the "campaign" at random times over the next couple weeks, then drop it and move on to something else.
I mention this because I want you and Trevor to understand my brother's behavior. He was basically treating our scheduled gaming group the same way you would treat your buddie's suggestion to come over and play call of duty - a random, low prep, low value activity.
We weren't playing that kind of game. I know that you bought the core book, the bestiary, and several parts of (or even the entirety of) the adventure path. I know that you spent Wednesday and Thursday nights re-reading previous content, reviewing current content, pre-reading the next adventure, and trying to smooth out holes as best you could.
In short, we weren't a bunch of unemployed/part timers playing something that had been thrown together, we were a group of adults who had to specifically set aside time, effort, and money in order to get together and try to have a solid, long-term gaming group.
I explained to him the differences, but I don't think he understood, and the game died as a direct result of his lack of respect - not to the game, but to the people playing it. There's nothing wrong with canceling, but it's important to have a good reason when doing so screws over three other people, and not only did he not have a good reason, he didn't think he needed one. That's the heart of the problem.