All these years later and I still have to laugh at how much MacGyver deplored guns. Yet blowing people away with homemade explosives was hunky-dory.
Simply, MacGyver NEVER did things the simple way. . .
Back in the 80s action heroes knew how to use high powered weapons in a totally safe manner. For example, take the A-Team. Every week they would shoot up a car full of bad guys with hundreds of rounds from a high powered weapon mounted atop their improvised tank, hundreds and hundreds of rounds. When they ceased firing the car would be a smouldering wreck yet you can be sure that thanks to the superior marksmanship of the A-Team the bad guys would all come crawling out of the car coughing and waving white handkerchiefs, perhaps with dirty faces or dissheveled clothes but otherwise unharmed. That, my friend, is precision application of firepower.
In a like manner McGyver could fill a room with toxic gasses made from regular household materials secure in the knowledge that there was sure to be a window that the bad guys would all safely could crawl out of, injuring only their pride in the process. Who needs a gun when you can do that?