If by "DA" you mean second strike capable, then it goes to a discussion of why it's needed. With that in mind, there are actually few pistols that offer the capability, and dollars are outvoting the guns which do have it.
There is no guarantee a round that will not go off with a first strike can with a second. Ejecting it and reloading will still be necessary. With a revolver that will happen as the cylinder turns, leaving the suspect round in the gun to come up again.
Frankly, the odds of a round not going off are less than getting into an armed confrontation, which are also pretty slim. And that is why most cycle their carry ammo thru the gun at the range instead of letting it ride for month after month. It keeps fresh ammo in the stack which hasn't been exposed to moisture or the environment.
Guns need to have certain features - like, a trigger - it boils down to which ones are preferred by ranking them in importance. Does a last shot slide hold open rank higher than a magazine disconnect, or does a second strike capability rank higher than night sights? Up to the user, but in a lot of cases we see the results of what the public currently considers important by what gets included and marketed with the gun.
Second strike capability doesn't really even exist in revolvers - and there is a perspective it's a gimmick in pistols.