You don't really believe that. If you do you are pretty ignorant. It doesn't even cost anything to start a fire if you do it right. No one is handing out free guns. Gasoline is cheap. There is a reason we have fire codes... because populated buildings on fire can be very lethal, and spread quickly.
Also, everyone thinks of a clock with a radio and a beeping timer when they think of IEDs. You can build an IED out of a light bulb and some gasoline. If people want to kill people they can do it no matter what you write down and call law.
Guns don't depend on people being in a building or the flammability of said building or many other circumstances that need to coincide for an IED or a building fire to kill people.
What was the last time we had mass murder by fire or by IED?
Many wild fires in California are set by people.
And many result in multiple deaths.
But I would say a fire starter is a different type of killer then a mass shooter.
I for one would prefer protecting my self from a fire then a shooter.
So if truly strict gun controls nationwide lowered shootings a lot.
But fires went up somewhat it could be a better trade off.
Tough call.