Comment 14 for bug 3896

The key message here is that if we encourage, say, bug reports in other languages, then we will have dozens of bugs that the developers of Gwibber can't fix because they don't understand them.
So, as a team, we understand that this excludes a certain number of people, as well as making it difficult for others, but the trade-off here is that the majority of the free software world can work together in a language that is already generally understood (as a pretty big example, programming languages themselves use English words).
We would absolutely love to be able to appeal to even more users and make them feel comfortable with the interface, but it is a requirement that the language doesn't become a barrier for everyone else at the expense of a few. If we manage to, say, get live translations with good quality, this may be possible in the future.

To be clear, most of the Launchpad developers aren't native English speakers, so this not a personal preference as much as it is a strategic decision to ensure collaboration as smoothly as possible.