Dry firing is not an issue with a good quality modern weapon. Some handgun designs like Glock require that you dry fire the weapon in order to field strip it.
Dry firing a handgun (with a snap cap in place) will help with trigger control.
You can have a snap cap in the Ruger SR9 or P345 and still ruin the firing pin unless you have a magazine in the gun. The magazine deactivates the FP safety. I for one don't really care for the idea of having to put a magazine in the gun to dry fire it. The issues with those two Ruger models is a design flaw.

Those who are serious about handgun shooting as well as action pistol pros, all recommend dry firing as part of a practice regimen.
I only think old school with old guns, ones that I know shouldn't be dry fired due to age etc. I don't dry fire rimfire guns, that will cause damage to the gun.
Many older non-inertial firing pins will be damaged with regular dry firing.

Now to be fair, Ruger isn't the only company turning out lots of junk these days. Smith&Wesson, Para Ordnance, Taurus (always a risk of junk with them), Kimber, and others are guilty too. Seems that high profit margins are way more important these days than making a decent product.

J.