Good hypotheses, all of these. Perhaps it might be useful to inquire, what determines a fetish? (I personally favor an explanation based on the psychological concept of "imprinting" and can identify in my own formative years (ie., prepubescence) certain experiences that may have predisposed me to a subsequent sexual attraction to hair on females .) Since we might agree that they are not the product of choice (any more than sexual orientation or eye or skin color are), then no more indivuduals will be prone to any particular fetish than are mysteriously drawn to it in the first place. Perhaps hair is also simply not as prominent a "secondary sex characteristic" than are others like those you mentioned--breaasts, etc.--and so not as likely for young males first to associate with pleasurable sensations than would be "soft lovely locks", etc. But, obviously, I'm no Einstein (or Freud or Adler, Fromm or Jung). I'm just a hopeless hair fetishist like the rest of you....