I have used the word triggered jokingly when socializing with college professors, in the context of talking about the challenges of dealing with a certain type of student that disrupts the classroom and demands coddling for their undiagnosed but deeply held beliefs regarding what they can handle mentally. Beliefs that trivialize the origin of the very real PTSD suffered by those for which the term was invented.
Perhaps when people make light of the word, they are not automatically making light of all PTSD sufferers as some might jump to claim, but of a certain type of person, which anecdotal and written accounts confirm the existence of. Perhaps just saying that if someone has used the term outside of it's 100% most serious context, they're a garbage person isn't a helpful generalization. Does someone who makes light of trigger warnings respect the PTSD of a former military officer? Do they respect the PTSD of people that had traumatic childhood experiences? Can you know the answers to these questions, based on knowing that the person once made light of trigger warnings or being triggered? I don't believe so.
Out there, someone exists who could listen to a former soldier talk about his PTSD and callously reply with something along the lines of "that's bullshit, what you're describing isn't real. Get over it." There are perhaps more who would reply similarly to an account of PTSD linked to childhood trauma. However, I believe this number is far lower than people on the internet seem to believe. Can someone make fun of something in one moment, and take it seriously the next? I think we have many examples of this (cancer, AIDS, race, and more have been the subjects of humor in countless comedy specials, TV shows, books etc), and thus I don't agree with the idea that someone should be castigated for laughing at or making light of something as if it says anything about their true feelings and beliefs.
Of course, the most extreme examples exist. I'm perfectly happy to dismiss Glenn Beck, Rick Santorum, or Rush Limbaugh because they have repeatedly stated their beliefs in the clearest of terms, and in action. These people's existence doesn't effect an argument between anonymous people on the internet, or while socializing with a group of friends.
On a larger level, free speech is important because ideas have to stand up and survive challenge. When one generalizes or labels people in a way that writes them off, cuts off communication and alienates people, it doesn't stop their ideas. It just tells them that they have to go elsewhere, and find people that don't reject them based on those ideas. There was a time when these sorts of interactions were mostly with real racists and other fringe groups. Now it seems to me that people are dismissed for their ignorance, for humor, for not immediately supporting ideas they've just been made aware of, for expressing doubts... And I don't find dismissing those people helpful. In fact, I'm afraid of what the future looks like if this is the standard going forward. I had a similar point in my more on-topic posts in this thread re: Joe Rogan, even if our OP didn't seem to understand.
That said, for those of you who are not interested in dealing with garbage people who have used the word triggered lightly, I suggest you put me on your ignore list. And see how much that accomplishes.