I've eaten sugar my whole life and I've never gotten diabetes!
While there are some perfectly lovely people whose medical knowledge is so lacking that this statement does get made, oftentimes reframing things helps to put things in perspective. Not everyone who eats sugar gets diabetes, and not everyone who experiences Trauma gets PTSD.
Some people want to understand, but can't. Others are protecting themselves. Others are willfully ignorant. Others are trying to share what's helped them, in the best way they know how. Regardless of why, it can be hurtful and frustrating, when the people we love best just don't get it.
Welcome to the forums.