Why would using the LED be a bad idea? Its just an LED so there's no heat, and it will damn near last forever. You'd be probably get rid of the phone before you'd have problems from the LED. Besides a drain on the battery, I don't see the problem unless someone ran the LED 24/7 for days on end.

If anyone needed a real flashlight obviously a good flashlight would be better served. But if you wanna find the remote in a dark bedroom while you spouse is sleeping, find something you dropped in your car seat or find yourself in a storage room looking for the light switch the LED on the BB works perfectly. Now if your the nighttime security guard, that by all means go get an 8-cell Maglite.