Realistically: To stop people from grabbing their belongings means to stop them having them in the first place. Getting rid of the overhead bins, forcing them to check EVERYTHING in but a very small bag they can wear on themselfs. Even then, you can't really tell them to keep their wintercoats on during the flight and they will grab them on the way out if there is any chance.
No, it is not nice, no it is not how it should be, but that is how it is.
Now which airline would want to sue passengers who have been through a "suboptimal" experience already? What would the impression be if other authorities did that? You get the evacuees in a room and all those who have their bag with them get arrested?
Again, if we want them to stop taking their stuff, then it has to go in the hold and not be reachable. Now if that is what we can realistically do and what we want to subject passengers to, others will have to decide. Not being able to work during a flight or even read from their tablet e.t.c. due to such rules might indeed cause a lot of folks to simply not bother anymore.
What should be done though is to finally enforce the handbaggage rules properly.