I really don’t like these sorts of “rules”. Use what you need to to get what you want. In strong light with modern cameras it is easy to shoot at 0.5/FL so why not. But in low light you have to trade something to get that. Maybe it means more noise or less sharpness. In those cases it is often best just to brace yourself and leave that sort of rule behind.
Even though none of the other statements in this thread is incorrect, I do agree that in photography, rules are there to be broken more then anything. To me, photography is a creative process. I have a certain rudimentary interest in technology, but only so far as that I understand what is going on when things are not going the way I want them to.
For everything else, the technology involved is of secondary interest only to the image results. In short, that means a tripod would prevent me from getting a photo more often then aid me in any way. Having to focus on shutter speeds would get in my way. I use the optimum I can get, but if that optimum required for correct exposure is longer then 1/FL, then that is the way it is. I take the photo rather then having to come back with a light setup.
I guess everyones needs and requirements are different however, and that is what makes it so nice to see other peoples takes on photography and the results they get, and compare them to your own.
My girlfriend uses a D800, never touched a tripod in her life, and gets results that, in my eyes, are good enough to sell. She also doesn't worry to much about this 1/FL rule. Just occasionally wonders why none of her images are completely sharp when viewed at 100%, only to find out during PP that the shutter speeds were abominally long (sunset photos at ISO 1600 and shutter speeds of 1/320th or slower on fast moving subjects for example)