These folks argue (with scientific citations!) that words can cause physical pain and stress, and that actions that cause such things are basically tantamount to violence. What's the difference, right? If I feel bad, what does it matter whether you said mean words to me or you punched me?

The problem is, words can cause stress in all sorts of situations because social interactions can be inherently stressful. There is no non-stressful way to end a relationship or deliver a bad performance review. But sometimes it needs to be done.

Punching someone is extremely different. It's not at all something that normally has to be done, unless perhaps you were just punched first. Physical violence is fundamentally different from speech because speech has an absolutely vital dual purpose of communication, which physical violence doesn't have.

To avoid calling a huge variety of legitimate speech acts violence, we'd have to redefine violence in some tortured way, like "stuff that causes harm and stress unless it was necessary/justified".

I don't think we should redefine the most emotionally salient words in the English language just so that activists' favorite slogans can be retroactively deemed logical.