Here are some numbers to ponder:
A typical car (40 mpg, average speed 40 mph, fuel 46 MJ/Kg), burns fuel at a rate of 46 kW.
So a journey of 30 minutes lights on, uses the same fuel as lights off for 30 minutes and 5 seconds.
So there is a difference, but it would be negated by 5 seconds normal driving, or maybe a 1 second burst of acceleration. Worse culprits for energy waste would be air conditioning, driving faster than 45 mph, traffic lights, roundabouts, traffic jams and so on.
On the subject of visibility, it is my experience (as a biker) that it is
lateral movement that people see (or don't see), so lights on all vehicles may enhance that effect.
PS Please try to use terms such as incorrect rather than BS - helps to not wind people up unnecessarily. 