Well for one, you probably don't want them to be apt-get in terms of installing binaries. We had that with Fink, etc. and it sucked and was outdated quickly. Homebrew is pretty solid though, probably better than what Apple would come up with. They actually helped make what you would like a reality partially by releasing the Command Line Tools so you don't have to bother with Xcode.

Why not? Binaries are so much better for a platform like the Mac (basically just 32 bit and 64 bit Intel architectures at this point, with fairly homogenous OS versions across the installed base). Why on earth make everybody waste their local machine cycles compiling something that should end up the same for everyone anyway?

Fink was only out of date because they weren't keeping it up-to-date (perhaps their builds weren't automated? That's pure speculation, I have no idea). Debian manages to keep things more or less up-to-date with more packages (and architectures) than Fink ever had.

Incidentally, if you put your Homebrew in /usr/local then it will often install using the "pour" technique which is pure binary distribution.

I loved Fink until it started languishing, and I love homebrew now: its "everything in git" philosophy and very-open-to-pull-request attitude of the maintainer make me optimistic that it won't slow down and become irrelevant like Fink did. I think that's the real difference between the projects.