Well said. I think we all have been the guilty cager. Just a few hundred feet down from my driveway, there is a large hill that shades a portion of oncoming traffic as they pass it. Bikes practically are invisible in this short stretch during the day.
I pulled out in front of a fellow rider a couple of weeks ago...when I was on my bike! A narrow profile, single headlight bike...never saw him. I was surprised when I took a peek in my rearview mirror and there he was.
IMO, the middle of the day when it is sunny is the worst time for visibility of bikes. They just wash out in the bright light. Cloudy days make bikes stand out more ... and more comfortable to ride to boot.