(Mainly) in Western culture, humans tend to believe that what other people do reflects their personality, responsibility etc., and disregard the extent to which the environment influences people. This is called the "fundamental attribution error". https://en.wikipedia.org/wiki/Fundamental_attribution_error
The point of the article is that the existing environment makes it easier for people - both drivers, and pedestrians/cyclists - to suffer gravely in the event they get distracted.
It's unreasonable to expect people not to get distracted - you can think of it as "baseline" level of distraction inherent to us all, which cannot be optimised beyond a certain point.
It's a much better solution to shape the environment so that people's distractions do not cost lives. _That_ is the point of the article.