I figured this would raise a few questions. Pope Bonifice was addressing a situation where "every" human was essentially a Catholic. There was no great knowledge of far flung peoples ignorant of Christ. There was no multi-generational tradition of Protesting. The world we know now is different than the world he spoke to.
The statement he made was absolutely true in the situation he made it in. Now we know a different world and people are not monolithicly Catholic by default. We have families that can't even remember when the last time one of them was Catholic. These people can not be expected to have culpability for not submitting to the Pope.
The need for all humans to submit to the Pope remains, but the cuplability of vast numbers of people to be capable of doing this has changed. Thus our interpretation of Bonifice's words has become more loose, to allow for invincible ignorance.
SD