The only reason to decock a gun, generally speaking, is if its a DA/SA gun and you want to start from hammer down. Otherwise you should be unloading it or storing it.
Citing 1911s and BHPs as having decocking issues (due to short hammers) is misleading and inappropriate -- they should be carried cocked and locked or unloaded -- as you certainly don't want to carry a 1911 or BHP hammer down -- as that forces you to manually cock before you engage. To make matters worse, some 1911s would be LESS safe AFTER being manually decocked than before.
I don't know of many other non-decocker guns with short stubby hammer. Got some examples? Especially if they're SA. Darned few that can be carried cocked and locked have short, stubby hammers. My S&W 4043 has a short stubby hammer, too - but it NEVER needs to be decocked -- its DAO and isn't cocked until the trigger is pulled!
Citing a P220 (which does have a stubby hammer, but ALSO a decocker) is misleading -- as it was designed to be decocked by using the lever. No need for a larger hammer, as it shouldn't never be started from the cocked position!
I don't find the "short" spur on a CZ to be all that short. I've also watched many shooters manually decock CZs at matches without problem. (You have to start hammer down in IDPA SSP division.) They just pay attention to what they're doing, and point the gun in a safe direction.
If you DO find the hammer to be short and hard to manipulate, all you have to do is put the thumb (or little finger) from your off hand under the hammer before its lowered -- or grasp the hammer with the thumb and forefinger of the off hand as you slowly pull the trigger. That is not rocket science. The process of decocking is not a fundamentally dangerous process.
If you had a negligent discharge with a revolver, its because you had a lapse -- that one time -- and weren't as careful as you should have been with a loaded gun. It was NOT because that particular gun was inherently dangerous during the decocking process. All guns are inherently dangerous -- they're designed to be.
If you want a decocker gun, get one -- but citing the difficultly of manually decocking decocker models with short hammers, or single action guns with short hammers, a reasons for preferring a decocker design doesn't make your case.
And, until you show me otherwise, I'll continue to say that any non-decocker gun can be decocked manually, safely, with only a modest expenditure of effort and attention.
