For the record, please don't drop my weights unless I am a body recovery. If you need to get me up and I'm not dead, there are a bunch better ways (as any rescue diver knows). For one, I am most likely neutral (or close) on the bottom, and a little one finger push upward will start the gasses in my BC and DS expanding and away I'll go. By the time I hit the surface, everything will be fully inflated and I won't have any chance of sinking back down. Besides, if you release my weight belt it will just get caught on my crotch strap anyway, and besides being in trouble, I'll look silly on the surface with it hanging from me.
The only time it might be a good idea to drop your weights is right after you jump off the boat without turning on your gas, without doing a gear check, without inflating your BC, without a buddy to help, without the skills to turn on your own tank underwater, and without being able to swim yourself up because you are overweighted. Then you might want to drop your belt so you can climb back onto the boat and start at once looking for a new hobby, like maybe bowling.