Exactly.
My comment was more related to the fact that the thing that appears to bother people a lot of the time is the term 'trigger warning' itself, partly because they have a mistaken understanding of what a trigger is, which you explained very well (and which was why I quoted you). The term seems to cause offence more than the concept of placing warnings on content, which is something that has been done on TV, for instance, for years without any significant number of people getting up in arms about it. The term 'trigger warning' seems to carry baggage, which is why a lot of people no longer use it, opting for 'content warning' instead. Given how misused the word 'trigger' has been in the past few years (no doubt related to the misuse of terms related to mental illness as insults or jokes, but that's a bigger discussion), I suppose it's not surprising that people want to distance themselves from it, so as not to provoke offence.