Yeah, I've also heard the mathematicians "prove" that an offset makes things more dangerous. All I can say is that it gives me a warm fuzzy feeling when boring through the dark African skies to see the opposing traffic slide past a few miles off to the left, rather than straight down the centreline.
I'm sure the above-mentioned maths boffs all have IQs greater than 200 - pity they can't see the practical side of things sometimes!!