Well, I didn't say the HIG is not not wrong. Personally, I do not use vertical mode exactly because of this, and also because the deskbar mode is much more useful on widescreen monitors anyway. Yet, most plugins have been changed to use vertical labels in vertical mode, so that all look similar. In fact, that was the one valid reason IMO for this change. You may want to discuss this on the mailing list. It is certainly a valid topic for other panel plugins too.
Well, I didn't say the HIG is not not wrong. Personally, I do not use vertical mode exactly because of this, and also because the deskbar mode is much more useful on widescreen monitors anyway. Yet, most plugins have been changed to use vertical labels in vertical mode, so that all look similar. In fact, that was the one valid reason IMO for this change. You may want to discuss this on the mailing list. It is certainly a valid topic for other panel plugins too.