As a new user, I am having trouble understanding the way trigger value plays a part in Actions. I've been told on IRC that it's needed to basically get it to perform correctly and that it's included in the default actions but I'm not totally sure why.

From the doc:

“Trigger value = PROBLEM” - so that only problem notifications are sent. This means that if you configure an action without setting any more specific conditions, messages will be sent for all problems. This makes the recovery message checkbox operate in a more intuitive way.

But this reads to me that only notifications will be sent that are only problems, not recoveries. Why does this make the recovery checkbox operate in a more intuitive way? Why is this needed to make the recovery checkbox more intuitive?