I have driven in both the US and a few European countries, and I would disagree with your proposed cause but agree somewhat with the effect. Having driven on long-distance road trips in the US, drivers are noticeably more competent than in (sub)urban highways, probably because the latter are filled with drivers who don't drive as much at those speeds. This is often inherently true in many western European countries in which driving usually has reasonable public transit alternatives so the selection of drivers on roads may tend to be more skilled and experienced.

That being said, in some European cities drivers are not very keen to stop for pedestrians in crosswalks, even when pedestrians are already in the median "island." I haven't noticed any US city of a similar size that had drivers quite so negligent about crosswalks.

In every US city I've ever spent time in, including San Francisco and Portland, you're taking your life into your own hands every time you use a crosswalk. Or even a sidewalk, as people will just turn into driveways without checking if the sidewalk is clear first.

I agree with one exception- Seattle. For all of Seattle's faults the drivers are very aware of pedestrians and very courteous towards them.

Agreed. Also, some college campuses I've been to are great with drivers stopping for pedestrians.