Large probability for bitcoin's price goes more higher.
We will see where price will go the next 5-10 years.I agree probably up.
Is it unfair for others who don't have any Bitcoin? No. Why?
Everybody has the possibility to own Bitcoin Tokens since 9 years.
It's all about educating yourself about the technology and make a decision in how far you believe this is a game changer and worth putting some money in it.
Furthermore you can buy very small fractions of Bitcoin. So there will always be a chance for the average perspn to own a bit of it.
It's even more than that. Bitcoin has its ups and downs, it's a highly volatile asset. Those who have the guts for it have plenty of altcoins to choose from for a start. If they chose well, when their altcoin becomes mature enough, they can sell for Bitcoin. And, with some luck, they can find a moment their coin is up (or Bitcoin is down).
Or, although it's not really feasible today because of the fees (but hopefully not for long), they can start with 0.01 BTC or even smaller amounts.