So, those small groups who knew about it, they mined Bitcoin almost for free in large proportion.
Your forgot small detail here. Noone could expect Bitcoin will gain so huge price in so short time.
Because of that even pioneers who mined 10 000 bitcoins on their single home CPU spend their 10 000 bitcoin on pizza and were very happy about it that it worked. That their coins actually was worth ANYTHING.
You could develop it like this, to have most bitcoin first, but it could be easily worth nothing in time. Bitcoin turns out true technological revolution.