Why pick on bars if you can't pick on the liquor store, the grocery store, the neighbor, the bottler, or anyone else who had a hand in a person having access to something they chose to misuse? Why not charge the car manufacturer, the car salesman, the DMV? Charge BVD for making the underwear he wore to go get drunk in. The gasoline supplier who produced the gasoline for his car.
Just how far can we spread collateral responsibility? I know the answer: just as far as a lawyer can see.
Generally, in gun forums, we find ourselves with folks who believe in the idea of individual responsibility.