Ubuntu 8.04 LTS server and desktop releases

The problem is that in an LTS release, you really don't want to be making significant changes
in behavior mid-release. For some of these bugs (eg, the pulseaudio issues and kernel
scheduler issues I linked to above), people are going to have to work around them because
they're pretty much broken by default.

Coming along post-release with a fix has a good chance of breaking the workarounds, which is
bad because entire point of doing snapshotted releases (particularly LTS releases) instead of
continuous upgrades like Gentoo is to keep intra-release updates safe. Fixing these problems
after the official release will be anything but safe.

You are correct that there's a greater incentive to keep the LTS versions maintained over
their (lengthy) term of support, but this is why it's imperative to get things right at the
time of release. Failing to do so results in broken behavior that has to be preserved.