I actually agree, they work great for drawing attention. The problem is, they're so distracting that they cause other problems. As a cyclist myself, I consider them a lot more selfish than bringing a steel cocoon with airbags with you.

Recently I met one of these idiots on a dark cycle path and I veered away from them instinctively (partly because I could see they were present but couldn't judge where they were) and then overcompensated and swerved behind them - very nearly hitting their child on a kid's bike behind! I hadn't seen their child because I was blinded by the adult's light. They probably thought they were keeping their child safe but they were really putting them in danger.