The greatest single issue that ties all of those things together is population density. In Canada we have probably six or seven major metropolitan centres with population densities that approach European population densities. In turn, those are the communities where you tend to find first-rate transit: the Torontos, Vancouvers, Montreals, Calgarys, and Edmontons. Outside of those, the population density in Canada drops dramatically.
When you don't have good population density, you tend not to have good public transit, because public transit really is a means of mass transit, and mass transit really depends on bringing a large population to a downtown core and then returning them. If you don't have that population density, public transit isn't necessarily your best option.