A lot of it has to do with:
1) reality- as noted before, not everyone has it within themselves to stand up to aggression
2) liability- if you're an employee of a business and you stand up to aggression, you may well expect your company to pay for your injuries (or death expenses) incurred while doing so. And if there is collateral damage, those others may go after your company as well. As a result, many companies state it is non only against company policy to resist, it is a fireable offense to do so.
3) law- a legal regime which has been drafted to foster such behavior is difficult to imagine, and has its own issues...like how well armed (and well trained) does the populace have a right to be
1) reality- as noted before, not everyone has it within themselves to stand up to aggression
2) liability- if you're an employee of a business and you stand up to aggression, you may well expect your company to pay for your injuries (or death expenses) incurred while doing so. And if there is collateral damage, those others may go after your company as well. As a result, many companies state it is non only against company policy to resist, it is a fireable offense to do so.
3) law- a legal regime which has been drafted to foster such behavior is difficult to imagine, and has its own issues...like how well armed (and well trained) does the populace have a right to be