Because once you realize the power of apt-get, you'll never be able to use anything else. And the real power of apt-get are the archives behind it, which will take the other disrtibutions a long time to compete with. In fact I don't think a commercial distribution ever would.
Fedora could come close with its archives, however they don't seem to want to have a "stable" supported distribution.
I've spent the last two weeks playing with Kanotix and am enjoying it very much. Could be my new distro. of choice.
The hardware detection works very well and the installation on to my hard was very easy. Kano, the distros developer, also includes some very helpful configuration scripts to assist in the setup. I also like the new (well, new to me) Klik (http://klik.berlios.de/) software store for use with Kanotix and Knoppix.