Whatever Canonical's reason for releasing Launchpad, that's beside the point I was making: there was a lot of criticism that a supposed "open source" company was using a proprietary and centralised app and not walking the walk.
Post-release (it's been out a year now?) you have to say that the release of Launchpad has basically been a damp squib and it's made practically no difference that it's free. People still use bugzilla/whatever, and those who clamoured for the release have made no discernible use of it.