Okay, so the law is the law. But what if your bike can't burn the headlight all the time? And many of our bikes fall into that category. Example;
My 350F comes with a 35/35 watt headlight. Barely enough to be seen at night, much less be able to see anything. So, the logical step is to upgrade to a decent wattage, say a 55/60 halogen( a common upgrade for back in the day). Okay enough for running at night, but the charging system won't take running the headlight all day, say doing a poker run or a trip. So by the afternoon, the electric start is useless. Thankfully we still have a kickstarter. And this is why some have made the change to LEDs for the other lights, to save wattage.
And then there's this. I don't believe the headlight will make us be seen any better. Many years ago(80s?) I got an insert with my tag renewal. It was a legal width(8 1/2") piece of paper, folded in half from a 17" piece. The instructions said to unfold it(a silhouette of a bike on one end, and a dot on the other) and look at the dot. In 10 or so seconds, the bike fades away. And sure enough, it did. My conclusion is that it's not lighting, or the lack thereof making us harder to see, it's the brain playing with us.