about 100,000 individual someones, each of whom mined (on average) 10 or so coins?
OK, first, you *can not* mine 10 or so bitcoins. There were no mining pools at first, and that is the only way people mine fewer coins.. And that's not really even correct.. Mining pools mine 25 bitcoins these days, and then share them with their members.. What we're talking about is directly mining coins here, which got mine 50 coins at a time for the first four years or so.
Also, IIRC, most of these coins are held by just a few addresses, not spread among 100,000. The entire population of the bitcoin community was probably less than a few thousand people during the first year.. During the first months it was more like 20 or 30.... maybe less..