A deliberate unwarranted insult is never justifiable. If you can't use logic to explain your grievance like an intelligent adult. I assume your over compensating in an attempt to mask some insecurity you have. In poker I assume that it's your inability to play poker well.
In my experience the ones who are talking smack in an attempt to tilt other players are extremely thin skinned. If you can counter their remarks cleverly, while not stooping to their level. They tilt rather easily.
When I first started playing
poker online. I would do this anytime someone started acting this way at a table. Regardless of whom it was directed at. Being as I really enjoy a good "debate".