THe problem is that if you install Ubuntu and your behind a buggy router then you may run into severe issues when trying to update your system.
In order to download the "fixed" kernel you need to be able to get on the Internet. If you can't get on the internet due to a "broken" kernel then how exactly are you suppose to solve your problem?
Catch-22.
The _only_ effective fix for Ubuntu, at this point, is to include the "fixed" kernel with the installer.
And I can understand if they can't pull it off. But it's going to suck for some people that they can't.
(Of course, I am fully aware that it's not Linux being broken, just the environment that Linux is expected to operate in has buggy network hardware sometimes)