without any steps in between for something as mild as someone trying to touch an object that belongs to him.

Again, you're assuming the offender's intent a priori, and assigning a low value of someone else's property for them which you don't have the right to do. Everyone has a smart phone these days, but you can't know whether the loss of that phone is a minor inconvenience to a person or whether it's their "home address" with the only contact information they have. That places a major value difference to the property to the owner that won't be visible to anyone else.

And we should always assume the worst of people and immediately attack them?

Certainly not, and from the context of the ad that's not what happened there. In the ad world the owner of the clubs didn't create the set of conditions that led to the grabber's actions, the grabber did.

Sane people, again, don’t go around assaulting other people at the slightest provocation. That you apparently do, or fantasize about doing so, is a sign that you are quite mentally disturbed.

Again, "slightest provocation" is relative. That's why we're having this long ass conversation: you've obviously never been down to your last two nickels and watched something critical fail because of the preventable actions of someone else. Lucky you, congratulations, and I hope that you continue to have that sort of luck going forward because you obviously don't have the toolset developed to handle that kind of situation. Your strawman and ad hominem attacks aside I'm happily sitting at zero altercations and hope that continues on for the rest of my days.

I also no longer have to wonder if long, monotonous safety briefings are really necessary; that nobody truly could be so stupid as to ignore all warning signs, social cues, pictographs of danger, lights, sirens, bells and whistles, because I can remember that you're out there somewhere oblivious to the world and its consequences and armed with all the world's knowledge about all possible events and outcomes and have them prejudged based on your interpretation of violence.