From the standpoint of access networks, physical issues, such as typical loop length (the distance between an end user location and a switching, routing or aggreagation point) are quite important. Digital subscriber line, for example, is directly variable with distance. Areas or countries with short loops will be able to support higher bandwidths, using DSL, compared to less-dense regions. Broadband gap?
Network cost also varies directly with loop length. Networks cost less, per-home, when density is high.
Most people forget that the United States never ranked higher than about 12th worldwide for fixed-line voice coverage, and despite that fact, nobody thinks fixed-line voice coverage has been a serious issue in the United States.
Then there are different market environments as well. In nearly all of the United States, there are two fixed-line broadband networks in operation, whereas in many other areas there is basically one facilities-based provider in each local market. From a broad capital allocation perspective, any national market will invest more to build multiple complete access networks.
Competing, widespread fixed access networks mean the ability to recover investment cost is much more difficult. That, in turn, means executives will be more cautious about investing. There is no magic here. Concrete circumstances, both physical and financial, mean different expectations of financial return in different markets.
And those expectations always are reflected in investment decisions.