Sorry. I am confused. Being a total a*hole ruining the flight for multiple passengers and FA's seems ok to you. But an ounce of comeuppance. That's not cricket. ? Maybe you should re consider your comments. The result seems fair and the punishment fits the crime.
For those that complain that passengers should not take affirmative action against others for transgressions on board, I think you are not being realistic in your armchair judgement.
You are probably the ones who complain, "The FAs should've done something about it, then didn't. Hence, I will not fly XYZ airlines again." When in actual fact you know you had the full initiative to do something about it, you just hopelessly relied on someone else to do it for you.
If someone was bleeding on the street, do you just walk by or just call an ambo / doctor and do nothing else? Or do you rush over and help bind their wounds?
If you saw someone having their purse stolen, do you just stand and call the police or do you try and run after the thief?
In saying that, although I agree something should be done about the a**hole passenger, I don't agree with what was the decided course of action, because it just seemed rather childish and the result would've felt rather childish. Perhaps a more diplomatic stand against the pax with other affected pax might've been better. If they abused the FAs, I would make sure that the FAs are reassured that the person is an a**, and a follow-up message promptly delivered to a customer service line. Perhaps you can make this reassurance as loudly as possible so the a** will hear it.
Back on topic.....
Luckily for me, I have never had to play jockey for overhead space. Yeah, I've been late to get space, so under my seat my bag has had to go. When I've sat in higher classes, luckily I haven't witnessed any dumbos trying to stash items there when they should be doing so many rows further down the aircraft.
Knowing that bag shoving is a natural part of travel, my bag and contents are 99.9% ready to deal with impacts, crushes etc. You never know with the rearrangement up there, what people will do with your bag. (Probably helps not to carry anything too fragile and stash it up there).
I'm not sure what I would do if I finally see such behaviour. My take would probably be to remove the item from the overhead and put mine in its place. If someone asked what's with the piece of luggage in the aisle, I'd say, "Well, it's not mine. Is it yours [referring to pax in the vicinity around me]?" No response? Report it to the FA as a suspicious package (or at least it doesn't belong to any of us in these rows).