I doubt its life saving capability is that significant. Yes I do agree that it helps people notice you better, because you're the only among the many with your front lights on. It's just normal human reflex on picking up things which stands out the most.
But look at it this way, motorcyclist have been riding their bikes with their headlights on for a vast number of years. Yet,they don't really stand out from the crowd, as everybody is riding with their headlights on.
So if every cars are to be fitted with DRL. Yes every, or large number of cars are fitted with DRLs. I don't think cars with DRLs then would stand out as much as it is now, due to the scarce number of cars with DRLs. There's just no 'standing out effect'.
So yes, i agree, it's more on the cool factor now!