I'll take a Glock over a wheel gun any day. The last time I fired my Colt Trooper .357 it stopped working. Never had that happen with a Glock. It's the AK-47 of the pistol world. Pull the trigger and it's going to go bang. Have your friend look at what the State Troopers and the local police carry. No police department today has their officers carrying a revolver. As an Alaskan, I only carry semi-automatics. Maybe a few old timers stubbornly cling to the notion that a revolver is better, but no informed person does.
A lot of folks prefer a handgun cartridge with more power, than is commonly available in automatic pistols. And even AKs (which you mention as a standard of reliability) malfunction - I've seen it happen, more than once.
I've learned over the years that every gun owner has an opinion. Some are based on real experience, others not so much. If you want to carry a Glock in bear country, knock yourself out - but your personal preferences do not make other guys, with other experience, in other circumstances, uninformed...