You know, this is all taking people further and further away from the fact that regardless of the technical ideals, pictures are made in the mind and caught via the camera.
surprised at such an attitude
. It's a given that any picture usually appears in the mind before the shutter is pressed, otherwise one wouldn't know what one was shooting. But in order to 'catch' via the camera what has previously appeared in the mind, one needs an appropriate shutter speed, otherwise the result will likely be considerably different from the picture in the mind.
Isn't the 1/FL rule as old as the hills? (Well, at least as old as the 35mm format).
Of course, if one suffers from Parkinson's in one's old age, it doesn't apply. One might then have to create a new rule such as 1/4FL or even 1/10FL.
One factor of the '1/focal length' guide for minimum shutter speed, which is sometimes overlooked, is that it relates specifically to the 35mm format.
If one applies the rule to other formats, one should use the 35mm equivalent of focal length, so a cropped format camera with a 50mm lens requires an 1/80th sec minimum shutter speed, and presumably an MF camera with standard 80mm lens requires a minimum 1/50th.
If that doesn't sound right, it's because one has perhaps overlooked another factor. The 1/FL rule relates to a requirement for acceptably sharp prints at an 8"x10" size (or 8''x12" without cropping), because that size used to be considered by many as the maximum size print for 35mm photography without grain becoming objectionable.
Clearly modern DSLRs and MFDBs are capable of much larger prints than 8"x10". The larger the print, the faster the shutter speed required for a hand-held shot to be acceptably sharp.
Of course, the new technology of Image Stabilisation changes the situation. Whereas a shutter speed of 1/FL using a 24mp DSLR is clearly inadequate if it is intended to produce a large print, a shutter speed of 1/FL in combination with VR or IS may be perfectly adequate.
This is a situation where you should make your own rules because each invidual's capacity to hold a camera steady will vary, and the style of camera and method of holding it will also affect the result.