Nice comment from Reddit (thx for link above):
NEO is a Share of the network, it's not to be used as currency. GAS is what you would use for transactions. It's just like a share on a company that gives dividends. You cant own 1.42 stocks of Tesla.
And regarding the decimal digit 8 (eight) digits after this comma is given as a tribute to the creator of the bitcoin itself, which is "SATOSHI NAKAMOTO". Either who's the first person to give a bitcoin decimal call.