That's because nearly every shooting is done by retards with minimal (or terrible) planning.
But yes, bombs make for better terrorist weapons than any rifle will.
However. OP didn't imply he was a terrorist, he simply wants a rifle that hasn't been castrated. Reminder to kill yourself if you unironically want to buy a semi-auto P90 or LMG.
Some weapons are simply not meant for anything other than fun-auto.