Dew, a quick look through a coin-price-guide book, and anyone will see that what you're saying is true. Compared to silver coins (dimes, quarters, etc...) there are just very few nickel dates that have good numismatic value. And then even when you DO find one of the few nickels that has a good numismatic date, nickels seem to always be orange corroded crud. Compared to silver, which can often times come out of the ground pretty durn good.
Reminds me of a park scrape demolition scrape some friends and I worked in San Francisco a few years ago. Since it was a scrape, so digging was a non-issue, most of us went into "relic mode", and dug everything conductive, no matter how small and flitty. At the end of a typical night, you might have 10 or 12 old nickels in your mix (V-nickels and Buff's). But invariably, they were corroded brown/orange cr*p, that you couldn't even read the dates on. And to get each of those, you invariably had to dig 50 low conductor pieces of cr*p to find them. But to the guys who were a little more discriminating, they ended up with a much higher percentage of silver, but perhaps only 1 or 2 nickels. They tended to get the choice SF mint silver, while the rest of us spent our time chasing little pencil eraser tops, zipper ends, etc... all night. It was a lesson in odds, for sure.