Despite all the bickering to be found online (by people who have never tried it), this isn't true at all. If you don't believe me, install a cog & BB lockring on a freewheel hub and try removing the cog with a chainwhip without removing the lockring.

I'm not saying it works as well as a proper cog/reverse-threaded lockring setup but the majority of bull**** you read online about suicide hubs is just that.