The answer to this question is the same as always; which do you shoot more effectively?
We can debate reliability or ease of carry, but it's the very first shot or two that makes all the difference. Can you put those first two shots on target, quickly? If you can't do it quickly, they'll shoot you first. If you're faster, but miss, the shots didn't solve the issue.
So, which do you shoot better? Carry that one.
I agree to a point, but think we must also consider the vast majority of civilian encounters occur at extremely close distances(usually 3 yards or under). I just can't see there being much of a difference in putting a couple of rounds on target quickly at those distances for most people. And a gunfight is not the only situation that needs to be addressed. I think it perhaps more likely the armed civilian will have to defend against assailants not armed with firearms, but with knives, makeshift impact weapons, multiple unarmed attackers etc. and in those scenarios and with ECQ in general, I think a revolver has certain strengths, especially in terms of getting off that critical first shot.