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?
If that is not a high enough count for you how about...
Then there is this...
and this...
Your argument of "ease" is flawed. The fact is if people want to murder they will find a way. In the UK they banned guns, then knife crime want crazy. They banned knives, now they stab each other with screwdrivers. Then they FUCKING BANNED SCREWDRIVERS, or rather walking around with them on the street without just cause.
Your premise is flawed.