For fonts Adobe licenses from third parties, most of those third parties require the embedding flag be set to "Preview & Print." But for fonts Adobe has all rights to (as well as those licensed from Bauer), Adobe sets the embedding flag to "Editable."
As for the advantage to setting it to the more restrictive of the two settings, I guess the idea is that somebody will need to buy the font to edit documents with it, so the foundry is hoping to make more money that way.
Regards,
T