So the background here is we get tons and tons of "bug reports" filed against X in the stable release which are utterly useless. And most of the time the user is really only looking for a workaround to get their system working again.
It's not hard to find a workaround (installing and running the current upstream kernel tends to solve a lot of "X" problems, and there's various kernel parameters to fiddle with). Problem is the reporter loses interest at that point and doesn't follow through with git bisection or whatever, so we can actually fix Ubuntu.
Users of the development release tend to be better behaved on this count, so we generally focus our efforts there. There aren't very many of us that work on X bugs in Launchpad; hardly anyone from the community works on them, and of the Canonical employees our job duties are more around the development release. Stable release bugs are more of an as-time-permits type activity. (Ironically the vast majority of the issues people file against X aren't actually bugs in X, but rather issues in the kernel or gnome or the window manager. They just file them against X out of habit I guess. We try to help them regardless.)
Many stable release users expect a quicker response than we generally can provide in Launchpad, and they want to know workarounds ASAP so they can get their system up. They don't want to hear all the technobabble about git bisects and kernel rebuilds. They certainly don't want to invest any more time into it than they have to. So they're not good candidates for bug fixing work.
Still, they deserve assistance, it's just that a bug report in Launchpad isn't going to get them what they want. Their report is just going to add to the log jam.
And so that is the purpose the above dialog: to try and steer the users to where they are most likely to get some sort of response and guidance with their troubles. Certainly there are plenty of support options out there; problem is that by and large most of them aren't very effective.
So, a couple years back I was bellyaching all of the above to Jorge over beers, and how much time I would waste invalidating these useless bug reports. At the time he was very gung ho about AskUbuntu, and so was pushing that. From what he described it sounded like it met these needs way better than Launchpad. Because of the high level of community activity new requests get addressed right away. Because of the voting, you're more likely to get effective answers. Because of the bounty system, users can "pay" to stimulate people to help them. Waaay better than Launchpad or any other support options. I had been putting time into writing up detailed troubleshooting guides in our wiki for things like X freezes, crashes and so on, but no one seems to ever be able to find those docs. Jorge felt that AskUbuntu was much better because it had a way higher google ranking, and people would be better able to find these answers that way.
And that is the real answer to why Ask Ubuntu is linked to from the X apport hook.
Anyway, now Jorge has asked that xdiagnose not encourage users to use Ask Ubuntu, and since he asked I've removed it. Instead it's just pointing them to a generic support page. I've also provided a "just file the dang bug report" button too. But I can't help but feel this is a step in the wrong direction, and puts us back to where we were. But if Ask Ubuntu is just marking the questions invalid too, that's hardly helping anyone so it's pointless to direct people here.
My original hope was not that Ask Ubuntu would be fielding bugs, but rather that it would translate them into a question like "How do I properly diagnose and report a problem with ___" and answer that, and then dupe all the incoming Q's there. Or at least point people to the X troubleshooting guides in wiki. Or even coming up with some spiffy hybrid solution that better leverages the strengths of Ask Ubuntu, Apport, and Launchpad towards actually getting these issues sorted out.