Hahaha! I was trying to keep it and short, avoiding writing a book, but you had to go there... Okay, yeah- it's an "ought" more than a flat prohibition. The issue is that there are a multitude of rechargeables with myriad voltages. Some voltages are within the range of specs that can safely drive the emitter of a Surefire lamp. Others are not. Over voltage can ruin the light. Since Surefire has no control over what kind of Chinese rechargeable batter you decide to slap in there, they simply advise you not to use rechargeables at all. Probably a sensible precaution for their marketing/legal department. If you do decide to use rechargeable batteries you want to make sure the voltage is correct.

I agree that Surefire doesn't keep up to date with the latest and greatest, but I think it's a bit off base to compare them with Maglite. The latter is truly stuck in the wrong century. While there are brighter LED lights than Surefire (and I own many of them) if I had to bet my life on one of them working I'd grab the Surefire every time. IMOHO that's probably why they don't play emitter-of-the-week with all the Chinese companies and don't try to walk the razor's edge with their microprocessors. They don't market to flashlight geeks- they market to professionals in the military and law enforcement fields. Surefire focuses on making pretty bright lights that are bomb-proof. For all that I don't think they compare to badly when it comes to light output, either. Most of my Chinese lights carry somewhat optimistic ratings; Surefire lights are generally the opposite. And my X300 Ultra weapon light is among the brightest hand held light I've seen.

Not trying to open a can of worms here, just making some observations.