[smeej]

So it makes about as much sense to ask why 2/3rds of the galaxies are "upside-down" from our vantage point, because there's no clear reason it should be something other than 50% in a sample size this large?

[jfengel]

Correct. On the largest scales it should be 50-50.

If it's not that would add a significant term to the Big Bang that nobody had previously expected. It would be a rather big deal... if it holds up.