I think you are sadly missing the difference. You are claiming that, since other means can kill people, we should do nothing about semi-automatic weapons.  When should guns be debated? Perhaps when they are used for their intended purpose, to kill. In contrast, what is the function of a pickup truck? While it can be re purposed, as can almost anything, that is not what they are for.  

YOU are the one that makes every terrorist attack about guns. Guns have nada to do with this. Drawing a false equivalency between trucks and guns is not, despite your belief to the contrary, a winning argument.