Agreed. It's a useless metric. It's like the "terrorism threat" color code crap. It'll never come down to a low setting because at the end of the day it's a propaganda tool to make people think a certain way (feel scared, in both cases). Setting it low is the same as turning it off and saying there's nothing to worry about which is totally counter to the goals of the people publishing these indicators.
I know I'm going to get down-voted because being scared of nuclear annihilation is kind of a point of virtue around here but if you take the emotion out of it it becomes pretty clear that the doomsday clock, or any other indicator that acts in a similar manner is nothing more than a propaganda tool. It may be propaganda for something you like but it's still propaganda.