That might have been the received wisdom a decade ago, but YUM/RPM work about as well as apt-get now, and - to be quite honest - I prefer YUM. I like, for example, that I use the same command to search for packages as to install them, instead of having to remember that on Ubuntu it's "apt-cache search FOO" instead. shrug YMMV.
perhaps my previous post was too polite. People that never actually _care_ to learn linux go from Redhat to Ubuntu (or stay right where they are!). People with an interest in the OS itself move to Gentoo/Funtoo/LFS.
I still use CentOS to this day (Asterisk), it's painful.