Because not talking about suicide and not confronting the issues it raises is the best way to stop it from happening.
/sarcasm.
Pity Truss couldn't resist a swipe at left-wingers, because the rest of her comment was sensible.
But she's right. it is the "regressive Left" that is making this happen. It's not
all the Left by any means, but then, we all like a bit of generalisation, don't we?