I hope it is not too late when he will realized what the value of bitcoin could be in some years to come.
I believe @OP friend is already at a financial freedom status. So @OP's friend think that he is not missing out on the opportunity if he will not invest in Bitcoin because he is already well-off and probably @OP's friend has business that is giving him way more profit than investing in Bitcoin.
My friend is also not into Bitcoin but he is getting richer each day because of his successful business and it is being franchised in different part of the country.
@OP's friend's argument makes sense, if only a few individual holds most of Bitcoin then, the market can crash instantly if these people decided to dump their holdings.
The context of the OP's thread isn't correct in the sense that, a person who learned something can't be said to not have interest in it.
It is possible that @OP's friend got interested on Bitcoin in some point but then realized the distribution of coins and thinks that there are few individual that has the capacity to crash the market and got disappointed knowing it.
Besides being interested does not mean the person will indulge himself on investing or using it. Probably it is the curiosity that pique his interest and found out get disappointed on what he found out upon researching about Bitcoin.
His friend's decision should be respected at all cost.
I highly agree, we must respect others decision and point of view about Bitcoin investment and the Bitcoin market system. Besides it is not our money that these people will use if they decided to invest but theirs. So we actually should have no say on whatever they wanted to do with their money.