Because the line of physical violence is pretty clear cut. The line at which someone gets offended is not and can vary drastically depending on the person, religion, current events, etc. Laws need clear definitions.
> Because as an American you put the border at physical violence but think verbal violence doesn't matter. You see that as freedom. I see it as a lack of culture. Far more than an ocean separates these two continents.
This, for instance, is clearly an insult; please report to the nearest detention center for your reeducation immediately. /s
But seriously, no; insults are subjective enough to be a terrible legal basis.
Is calling someone fat when they are indeed fat an insult? It obviously depends on context, intent, and delivery. Any definition is going to be nebulous.