> Debian maintainers who already have enough bugs on their packages are obviously not interested in even more bugs, but those who are maintaining niche packages, with few reports, might be interested by the user feedback available in Launchpad.
If you maintain a (small) package in distribution X, yet never have a look at what is happening to the same package in other popular distributions Y and Z, then it means you are more interested in having "X maintainer (Y sucks)" printed on your business card than in actually performing the maintenance.
Unfortunately this does happen. Sometimes you find a bug in distro X that has been patched many months ago in Y, and the X maintainer is surprised when you copy/paste the patch into his mailbox.
In a perfect world we would all be using the Single True Great Linux Distribution and there would be only one bug tracker to follow. In the real world it does not look like such a massive effort to browse a few of them and deal with the corresponding duplication. I mean except for big and fast moving pieces like Xorg or the kernel.