I agree with the basic premise that in general, there are more things that can go wrong with a semi-auto than a revolver.
However, in my shooting career I have had several issues with revolvers:
- Colt Detective Special snubnose I had bought used that apparently had a slightly loose barrel. During firing the barrel would rotate enough that the ejector shroud would catch the ejector rod making it impossible to dump the spent rounds, not to mention the front sight slowly moving to the right with each shot.
- S&W Model 60 (original, not the current ones) that I had taken to a lazy gunsmith for a trigger job - all he did was back off the mainspring a few turns and it wouldn't reliably strike the primer, causing failures to fire. Easily fixed, but still a failure and I'm glad it happened on the range.
- S&W Model 66, when rapid firing and reloading the cylinder would get hot and expand enough to greatly increase the resistance against the trigger just to turn the cylinder. That was also fixed and unlikely to be encountered in a normal shooting situation, but it happened to me on the range.
I've also seen cases due to improper maintenance or cleaning where a revolver failed to work or had a malfunction due to things like a screw backing out during range fire or gunk under the extractor star. One day when I was at the police academy another trainee's revolver actually came apart on the range - I have no idea what the issue was, other than another trainee yelling out to the range officer "his gun fell apart." It was a S&W revolver.
I've also had my share of occasional stovepipes, failures to feed, and failures to fire (bad round or light primer strike) in autos, so none of them are 100%. I've got one auto that will jam once per mag on Sellier and Bellot FMJ ammo, but handles all others flawlessly. I've got two that have never had a problem yet (Gen 4 Glocks) but I had a Gen 1 Glock (back when they first came out and didn't have a Gen number) that would stovepipe every so often.
The only advice I can offer is to shoot ANY gun system ("system" includes the grips, ammo, magazines, speedloaders, holsters) that you plan to carry or rely on for self defense, enough to make sure that the entire combo works well, you know how to use it, and is in good mechanical condition.
My impression is that the typical shooter (not the typical gun-forum member) buys a gun and two boxes of ammo, shoots one box through the gun at a range (maybe during their permit class), loads it up and leaves it in a drawer for the next 20 years. Perhaps the higher percentage of "reliable for the first 5/6/7 rounds" for a revolver makes more sense for that type of shooter.