I don't think this is a good idea, and I don't recall particularly well that it was decided as a team that we would do this. I think there are very good reasons to translate the log that are customer-centric. Logs are primarily for the users and not for us developers, so we shouldn't base our decision here on what is best for us. Users are going to expect the logs to be translated into their own language. Also, many of the users who will contact us for support will be communicating with our support in their own regions, and those support teams will appreciate the logs being in their language as well.

We can always ask bug reporters to resubmit log messages in English if we receive them in a language we do not understand, but if we only write the logs in English there will not be much help for them in reading them.