I thought we were talking about the "arbitrary" choice of Longitude 0. What's the political (and not economic) basis for the later IDL modifications?

That fails to make the first choice any less arbitrary - the choice was made to line up with existing sea charts - which of course used the Greenwich as 0 - but Greenwich as 0 was an arbitrary choice in the first place - not all arbitrary choices are bad ones, that was the crux of my argument in the first place.