I think this post raises a few issues, so want to deal with each independently:

1. 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!?

2. 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?).