The final drawback to this is that we'll all be completely insane. The human
mind does not accept the casual manipulation of the very fabric of reality
with particularly great aplomb. And the odds are nearly 1:1 that an overworked
grad student will unknowingly initiate a chain reaction that opens a door
into the anti-matter universe, allowing the daemonic creatures within to
escape their other-worldly prisons, and feast upon the flesh of the innocent.