Security updates from day1 with Kubuntu

I thought GNU+Linux was meant to be more secure than Apple and Microsoft's offerings.. you'd be fooled by the number of security updates needed on a clean Kubuntu 7.10 install. Everything from printing (CUPS), e2fsprogs, ghostscript, libflac, libpng, libxfont, mysql-common, openssh-common, openssl, perl, pidgin, samba and xserver-xorg-core need updating! already! at least they have fixed all these flaws since last September.. but why were there so many in the first place?