Using a minimum prominence to define what is a peak is obviously necessary, because otherwise every little bump and rock on a landscape would count as a separate summit. But the choice of what that cutoff should be is arbitrary, of course. For many, that choice is 300 feet.
I personally think that if we are going to choose a number, it should at least only be as arbitrary as the size of our planet, using a dimension based on it, which is how the metric system is based. (One meter was established as one ten-millionth the distance from the Equator to the North Pole.)
The value of prominence would still be arbitrary, but at least it would be based on something specific to the planet. So 100 meters makes more sense to me as a prominence cutoff for defining what is a peak.
Of course the value one hundred and using powers of ten is only a consequence of the number of digits we have on our hands. If humans had only 8 fingers, we likely would be using an octal system, in which the number one-zero-zero would equal 64 decimal. A 64-meter (100 octal - meter) cutoff would be a lot more fun, as it would make for a lot more summits being defined as peaks!
(One-hundred meters is about 328 feet, and sixty-four meters is about 210 feet.)
