I think this post raises a few issues, so want to deal with each independently:
Cryptocurrency mania is like the dot-com boom: Having lived through the latter (I had, like, 48,000 options in a company that went nowhere), I would agree. Ultimately, cryptocurrencies are poised to be transformative, but no single cryptocurrency is the clear long-term winner yet. That's the important part; we can't pick the winners now. Go back to the dot-com years and see how many companies from back then simply don't exist anymore. Think Bitcoin's the winner long-term? Ever heard of Yahoo!?
Not wanting to participate on Steem due to financial reward: I get this from an economic perspective, as it's the declining marginal utility of an additional dollar. If your friend is independently wealthy, it makes sense not to be motivated as much by the money. However, if your friend is already participating in social media, but not Steem, then there should be other motivations at play. For one, the conversation on Steem (from what I've seen so far) is better than most of social media, due to the reward structure. For two, the capture-attention-sell-to-advertisers model in other social media channels is hurting users, and society. So perhaps your friend can join and donate his Steem to a worthy cause (does Steemit make this easy?).
Speaking of Bitcoin, I think the entire future of BTC depends on second-tier scaling solutions such as the Lightning Network. I have decided not to invest in Bitcoin any longer but buy alts instead. The bull run of Ethereum, Litecoin, Monero, Dash, IOTA, ZCash and a few up and coming coins has demonstrated that they are fully capable of taking Bitcoin's place if it should stagnate.
My friend doesn't have a Facebook account, either, and I think he quipped he did not want the money just because I suggested that he join Steem for the monetary benefits. He is certainly wealthy enough to not need to work for a living but that is a much more a function of his low expenses than his high net worth. He is a bachelor and has no children and, apart from travel, has always led an Uncle Scrooge kind of lifestyle. My friend had a 15-year career as a research engineer working for a major corporation, the division of which he worked at fell victim to creative destruction. After that, he decided he'd had enough of serving a corporation. I don't think he could very well afford to be a patron of anything. He lacks social media presence and may have been reluctant to join Steem to begin with but I sensed a whiff of contempt for earning money by means as tulipy or otherwise suspicious as Steem. ;) (I had explained Steem to him in a conversation that took place several months earlier.)