Surely kids should limit themselves to only crossing on green (well, until they grow out of it) but I've taught my children to watch the cars first, not the lights. A green pedestrian light doesn't mean there are no stray cars running red lights or turning-but-not-yielding. It's cars that injure people, not lights, so focus should always be on cars.
That's not why people get riled up even if they think it is. Adults constantly do things in front of children that children cannot or should not do: cooking, handling power tools, driving cars, smoking drinking, etc.
For the most part, this is not a problem, people just explain their kids that these are things that they cannot do now but will be able to do later (hopefully explaining why).
But people don't put crossing the road at a light in those terms, they tell them nobody can safely cross the road safely when the light is red. So an adult doing just that and being safe directly contradicts your message and your authority. It makes you look dumb. And that's why they get riled up.
We should just treat the red light as an aid for the young and infirm and explain it to kids as just that.
I learned to ignore them. The speed limit on the streets where children frequent are max 40 and even lower around traffic lights. Drivers should keep looking and assume neither children nor adults will follow traffic rules. You just need to learn to be defensive if you are navigating tons of steel inside a densely populated area.
Children learn by imitation. That, and not the fear that the child might run after you (?!), is the reason why it’s frowned upon to cross red lights in front of children.
But shouting at strangers is also a bad example. I hate the unbeatable "but think about the children" argument that seems to haunt many discussions. Let the families educate their own children. Educate the drivers that children may randomly jump to the street, may also stay there and not try to evade or do who-knows-what so they should be more careful driving through the city. That's actually the case in Germany, training for a license includes learning to be ridiculously (but usefully) defensive.
As a cyclist in Malmö, Sweden, I wish I could shout at some people sometimes. But truth is that people cross against red all the time with no consequences.
