The few of points I've made about this are: 1. The Xcode 4 download compared to Xcode 3 is basically just a different IDE. The gcc version is, for all intents and purposes, identical. There's nothing stopping anybody from just installing that if all they need is the toolchain. 2. The other big 2 OS's (Windows and Ubuntu) don't have any build tools installed by default either. Granted they are just an apt-get away on…
If I wasn't a dev, I'd be pissed to find out some compiler toolchain IDE gongshow eating up 5-15GB of my disk space Yeah, but the essentials that most command line builds require wouldn't even take up 10% of that. Apple already wastes gigabytes on printer drivers and extra languages you don't need.
No, they didn't. For example, Snow Leopard downloads printer drivers from Apple as you need them.