Asking questions is not discussing previous content. I am curious as to why there is no recourse for victimised buyers?

There is a recourse; first report the threatening message to eBay.  There is a link on the message to report it.

You did the right thing to report the person to police.

But why did you cancel the PP claim?  I know, you were scared, but if you re-open it, as you now seem to want to do, you will not be scared anymore?  In that case call PP (as I already suggested) tell them the story, fax them the police report and ask if they could reopen the case.  Considering that you closed under duress, they may do it, at their discretion.  How much money is involved?