Murder is a disproportionate response. Making it legal to throw or smear poop on someone's face would be approximately equal in my mind to public smoking. You want to smoke? Fine, control the entire byproduct so it doesn't enter the personal space of others. Oh you can't control it? Sounds like you're out of control. Well I can get all out of control too, here's a poopstache. Yes this would be assault with a biohazard, and so is 2nd hand smoke.

Strong rhetoric but do you have the same view about driving a vehicle that has noxious emissions (and we're only recently discovering quite how noxious) that inevitably enter the personal space of others? Can we assume you don't have one?

Meh, that's a stawman argument.

We grudgingly accept the emissions from cars because of their other usefulness.

If we could make cars with no emissions and no other negatives, gas-powered vehicles would surely be outlawed very soon.

Smoking has no useful purpose and frankly it's ridiculous that some people feel they are entitled to put other people's health at risk because of their own addiction.

Of course you can control it. In many locations it is effectively controlled where only those wanting to have poop thrown in their face will and the rest can go on without it since the vast majority of zones are poop-throwing-free (in the places I am referencing).

In the town I live in, smoking is only allowed in adult-only establishments. And those allowing smoking are the minority because many business owners realized their customers don't want it at all. Best of all worlds and the state didn't have to completely outlaw its public indoor use, just restrict it.

"Best of all worlds" in your opinion is a world where people have to deal with unnecessary and unwanted toxic gases in only a minority of establishments?