Because one of the things about most of the focus of current terror threats (in Europe, I mean) is the terrorists do not spend ages worrying about RC model or mobile phone detonators, escape routes, avoiding surveillance and all the stuff that made it so much easier for security services and harder for terrorists in the 1980s.
They frequently blow up with their bomb - and with that mind set are quite happy to use insanity sauce recipes for TATP - which you really need a death wish to mess around with.
The latest batch of terrorists are very far from sophisticated or even security aware and Amazon is exactly the kind of place they’d look for parts… The PIRA would have run a mile from any of the recent European attackers - especially the ones who kinda gave up and hired cars and bought knives.
