I think Cameron’s comments refer to the geographical ‘easiness’ of hosting an Olympics in more open country, as opposed to a huge city like London, which is geographically in a more packed area.
IMO his comments werent a dig at the 2002 games being in some sort of ‘backwater’.
If anything, that negates his criticism. The infrastructure exists in a large city for operations on that scale. The logistics are a bit more of a challenge "in the middle of nowhere."