How can you be sure that SNakamoto is a collective?. I don´t say it´s not, just that we can´t know for sure... unless you belong to the collective
Why there´s that urban myth about Satoshi been a collective?
It's just common sense deduction...I think it is unlikely that a single person could do everything alone, it is something too big and embracing too many different disciplines...anyway there is obviously still a chance that Satoshi was just a single person, in that case he/she would really be closer to a demigod than to a human, like a modern Prometheus (no Frankenstein references intended)