Kernel upgrades = security upgrades

[Fraser Campbell <fraser@baxter.net>]

I am curious as to how the kernel upgrades in Debian are done.  Recently I
set up a new slink system.  The kernel installed was 2.0.34 (older boot
disk).  I added "deb http://security.debian.org/ stable updates" to
/etc/apt/sources.list.

An "apt-get update; apt-get upgrade" grabbed several packages 4 or 5
packages from the various sites and upgraded them.  The kernel was not
upgraded.

My question is, should kernel upgrades not be part of the normal updates? 
I know that there were there security problems fixed between 2.0.34 and
2.0.36.  In light of this shouldn't "apt-get update; apt-get upgrade"
replace the kernel?  I realize that "apt-get install kernel-image-2.0.36"
does the trick but to my way of thinking it should be an automatic upgrade
just like all other security issues ...

Also, I believe additional security problems were fixed between 2.0.36 and
2.0.38 but no kernels newer than 2.0.36 (at least in the 2.0 tree) are
available in slink.

Please don't take this as critism, it is a question.  I just don't
understand why the kernel upgrades aren't automated like all other software
updates.

TIA,

Fraser