Panic/anxiety attacks are not a silly little thing. They were portrayed somewhat accurately in Netflix's recent Jessica Jones (she even uses a common grounding tactic to prevent them, like street names from childhood), and in Love and Mercy, that biopic of the Beach Boys' frontman. Having had close experiences with people who have panic attacks and see them getting triggered by being reminded of certain incidents, I can tell you that panic attacks are not fun, and those suffering from them are not faking, nor are they being whiners. With time, it's possible to get over your triggers, but it's a long healing process. During healing, trigger warnings are the same courtesy as signs saying that people with heart conditions or expectant mothers shouldn't get on certain carnival rides.
But people now on the internet say stupid shit like "triggered much?" for what was once called "u mad bro?" And whether exaggerated or not, it seems that this kind of "triggering" is what UofC seems to be speaking out against. That's not what a trigger warning is for.