The people who designed it supposedly wanted a flashlight that would last for the entire time they were hiking the Appalachian Trail with no need for a spare battery. I agree there are much better flashlights available nowadays, but if this thing can really last that long on a single 9V battery then it easily outlasts any other flashlights I've ever tried, and I own some really premium ones. I can say, at least, that I've had this one for a few years and it's still running on the original battery. Having an actual mechanical switch, as well as a very simple driver circuit that just uses a resistor to control power flow to the LEDs, makes it much more energy-efficient than the software-controlled multi-mode flashlights available nowadays.

But yes, the reason it became a modular running-light for my RCs is because I almost never used it for its original purpose.