This summer we've been having a lot of this:
Sometimes it's nice to run the light just to add some warmth and brightness to the dreary scene.
On the open highway in fog I appreciate the power of the Superflash blinky taillight. I don't use it in good weather because the sight lines are mostly good and I wear bright (but not harshly bright) clothing. In reduced visibility I want to give overtaking drivers as much time as possible to realize a slower vehicle is there.
To reach distracted drivers, someone needs to invent a device that will broadcast a text alert to any cell phone in active use within 100 yards. Don't bother trying to get idiots to improve their driving habits. Just send them a text of your own. "Cyclist ahead! Eyes on the road, doofus!"