there is no reasoning george, unless the seeders are in the business of wasting time.
generally, I agree with you. although if you've got a 16 bit source and you want to do a lost of post-processing work on your computer, I'd say its better to work with an internal resolution of 24 or 32 bits, and then apply dither once, at the end, to get yourself back to 16 bit.
however, based on the torrents that I think you're talking about, that doesn't seem to be the case, in which case I agree with Tim - seems pointless to me.