Why do they still make revolvers when we have automatic guns?
What are the benefits of the revolvers?
Revolvers are simpler to manufacture, maintain and operate, and you can check the # of rounds left easier in a revolver. Jamming is a lesser issue, but with revolvers there is no “limp-wrist” jam, or bad ammo jam. You just pull the trigger again.
Everything Terr said, plus the fact that a revolver’s grips can be swapped out, which allows the gun to be fitted to pretty much anyone’s hands. With most semiautomatic pistols the grip is an integral part of the gun’s frame, so if the distance from the back of the grip to the trigger is not correct for your hand or if the grip is too wide for your hand you can’t alter it, and you’ll never shoot that pistol well.
And of course here’s a completely useless answer for you: because there’s a market for them. I mean, seriously, they are still made because people are willing to still buy them 
I don’t own any guns (yet), but the first one I plan on buying will probably be a revolver because I frankly just like them and the way they look and operate, despite any advantages they may have over magazine loading handguns.
Everything Terr and artemis said, especially concerning the greater simplicity (which provides more potential for reliability, durability, low cost, ease of use).
Also, revolvers can more easily use very long/powerful rounds than magazine-fed pistols. You could use non-magazine fed pistols but then you’d lose nearly all the advantages that pistols typically have over revolvers.
Plus, they tend to look better which I think can matter, especially for private sales.
ETA: See above for the Rule of Cool.
Why do they still make manual transmissions when we have automatic transmissions?
Some people like them that way. And they’re cheaper!
Got that right! Revolvers range from decent-looking to work-of-art gorgeous. Most modern pistols, in contrast, are butt-ugly. (Except for 1911 pistols, which ooze cool.)
It seems funny that something as trivial as looks would matter when selecting what is after all a lethal tool, but it does.
You don’t have to pick the spent brass off the ground.
Not many automatics can take down at deer at 100m or farther (assuming you’re a good shot, and you don’t have a rifle.)
If I’m not mistaken, a revolver with the hammer cocked is more accurate for a given barrel length than an automatic. Slower rate of fire, but less play in the moving parts. At least that’s what I was told, never actually tested it myself.
Revolvers can handle far more powerful ammunition. .454 Casull and S&W .500/.460 as examples.
As a rule, the fewer moving parts a firearm has, the more accurate it is. That’s why modern military snipers use bolt-action rifles.
Fewer moving parts:
I’m not sure how this plays out for a revolver though. Fewer moving parts= less potential for variation between shots=more potential for consistency of trajectory=accuracy.
But the whole concept of a revolver is that the chambers move. Even if precisely lined up, it still remains that in a pistol, the chamber doesn’t move relative to the barrel and they’re often the very same piece of steel. In a revolver, there has to be some variation in how the chamber and the barrel line up (bit to the left, bit to the right).
And manufacturers like Freedom Arms(.454 Casull and others) bore the cylinder in line with the barrel.
Revolvers, if they are good well-made guns, involve a good deal of hand fitting and skill - skills that are decreasingly available and consequently command high wages. Much of the remaining market is Western-style ones which trade on nostalgia value and which are mechanically simpler. Once police departments discarded revolvers they became ‘uncool’ (and the second-hand market was burdened with large numbers of ex-police guns).
The reason for this is on a semi-automatic pistol the slide (the part you pull back and release to chamber a round) has to have a spring that matches the recoil force of the round. For a very powerful round this would make the slide excessively hard to pull. The major exception is the .50 AE Desert Eagle, which instead of using a slide spring to cycle the action (“short recoil”) uses a gas-operated mechanism similar to how submachineguns work.
I have a range on my property, have shot with countless people over the years, have trained many, etc. Here’s my take on it:
If you’re going to carry a handgun for personal defense, your level of familiarity with the weapon will determine if you should carry a revolver or semi-auto. If you do *not *train on a very regular basis, but still want to carry a handgun, you should carry a revolver, not a semi-auto. You should only carry a semi-auto if you train with it on a regular basis, and can manipulate the controls without thinking.
And this is why some criminals prefer revolvers to semi-autos. Less evidence is left behind.
Not to mention revolvers, given their lesser amount of moving parts, can tolerate cold, rain, and snow much better than an automatic can. Freezing up the oil in your semi is not a good thing. The revolver, on the other hand, is not reliant on such lubrication for operation. (except perhaps on the point of rotation for the cylinder, but that can tolerate dryness)
I had a conversation last month with someone who lives in the Alaska wilderness on a regular basis about this. His gun of choice out there is a big whoppin’ revolver.
Because when in bear country he wanted to be sure the gun would fire. He isn’t as confident about semi automatics. If the situation comes up, he needs to be sure the gun goes boom. every. single. time.