[jdub]

Lots of reasons:

- everyone has better things to do than compile software they didn't write

- a good distro has probably tested it on a bunch of hardware, and hopefully signed it (or at least the packaging), so you know it was securely acquired and built

- you won't learn much at all about the Linux kernel by compiling it... you may learn a tiny introductory about about it by configuring it, but that's still not very much at all, really (it may seem like a lot when you don't know how to measure what you're learning)

- what you should learn from configuring and compiling a Linux kernel is that you don't ever want to be in a situation where you have to do it again (without a really spectacular reason, or being paid)

- if you're compiling a kernel because your boot partition is small... make it bigger, or don't have one at all. come on.