The whole problem with the "but everyone makes mistakes" mentality is that some people actively tempt fate on a constant ongoing basis. They aren't just making mistakes. They demonstrate a pervasive pattern of recklessness. They aren't just "screwing up occasionally". They are screwing up constantly and it's only because of the vigilance of other drivers that there aren't even more accidents and fatalities.
It's similar to how some companies approach how their products are engineered.