They way I see it is this, and I know it's a simplistic way of looking at things but it really is simple.
We are all somebody's child, if you would be outraged by somebody doing to your child what you've just done to someone else then don't do it. Whether that is a close pass, barging into someone,walking out into the road while texting and so on.
It all boils down to what everyone wants but doesn't want to give... Respect.